420123440 has 80 divisors (see below), whose sum is σ = 1121713920. Its totient is φ = 144725760.

The previous prime is 420123437. The next prime is 420123449. The reversal of 420123440 is 44321024.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (420123449) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 4157 + ... + 29283.

It is an arithmetic number, because the mean of its divisors is an integer number (14021424).

Almost surely, 2^420123440 is an apocalyptic number.

420123440 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 420123440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (560856960).

420123440 is an abundant number, since it is smaller than the sum of its proper divisors (701590480).

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

420123440 is a wasteful number, since it uses less digits than its factorization.

420123440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25170 (or 25164 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 420123440 is about 20496.9129382939. The cubic root of 420123440 is about 748.9605987106.

Adding to 420123440 its reverse (44321024), we get a palindrome (464444464).

The spelling of 420123440 in words is "four hundred twenty million, one hundred twenty-three thousand, four hundred forty".