421220400 has 120 divisors (see below), whose sum is σ = 1357777680. Its totient is φ = 111621120.

The previous prime is 421220383. The next prime is 421220417. The reversal of 421220400 is 4022124.

It is an interprime number because it is at equal distance from previous prime (421220383) and next prime (421220417).

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 421220400.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 206586 + ... + 208614.

It is an arithmetic number, because the mean of its divisors is an integer number (11314814).

Almost surely, 2^421220400 is an apocalyptic number.

421220400 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 421220400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (678888840).

421220400 is an abundant number, since it is smaller than the sum of its proper divisors (936557280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

421220400 is a wasteful number, since it uses less digits than its factorization.

421220400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2223 (or 2212 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 421220400 is about 20523.6546453111. The cubic root of 421220400 is about 749.6118880824.

Adding to 421220400 its reverse (4022124), we get a palindrome (425242524).

The spelling of 421220400 in words is "four hundred twenty-one million, two hundred twenty thousand, four hundred".