420400644 has 24 divisors (see below), whose sum is σ = 992755680. Its totient is φ = 138444864.

The previous prime is 420400639. The next prime is 420400657. The reversal of 420400644 is 446004024.

It is a super-2 number, since 2×420400644² = 353473402951229472, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 210049 + ... + 212040.

It is an arithmetic number, because the mean of its divisors is an integer number (41364820).

Almost surely, 2^420400644 is an apocalyptic number.

It is an amenable number.

420400644 is an abundant number, since it is smaller than the sum of its proper divisors (572355036).

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

420400644 is a wasteful number, since it uses less digits than its factorization.

420400644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422179 (or 422177 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

The square root of 420400644 is about 20503.6739146915. The cubic root of 420400644 is about 749.1252877902.

Adding to 420400644 its reverse (446004024), we get a palindrome (866404668).

The spelling of 420400644 in words is "four hundred twenty million, four hundred thousand, six hundred forty-four".