420431640 has 128 divisors (see below), whose sum is σ = 1313452800. Its totient is φ = 107573760.

The previous prime is 420431621. The next prime is 420431653. The reversal of 420431640 is 46134024.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 420431640.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 303750 + ... + 305130.

It is an arithmetic number, because the mean of its divisors is an integer number (10261350).

Almost surely, 2^420431640 is an apocalyptic number.

420431640 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 420431640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (656726400).

420431640 is an abundant number, since it is smaller than the sum of its proper divisors (893021160).

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

420431640 is a wasteful number, since it uses less digits than its factorization.

420431640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1497 (or 1493 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 420431640 is about 20504.4297652971. The cubic root of 420431640 is about 749.1436982574.

Adding to 420431640 its reverse (46134024), we get a palindrome (466565664).

The spelling of 420431640 in words is "four hundred twenty million, four hundred thirty-one thousand, six hundred forty".