401264640 has 312 divisors, whose sum is σ = 1594689408. Its totient is φ = 91422720.

The previous prime is 401264627. The next prime is 401264671. The reversal of 401264640 is 46462104.

401264640 is a `hidden beast` number, since 4 + 0 + 12 + 6 + 4 + 640 = 666.

It is a super-2 number, since 2×401264640² = 322026622628659200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1290085 + ... + 1290395.

It is an arithmetic number, because the mean of its divisors is an integer number (5111184).

Almost surely, 2^401264640 is an apocalyptic number.

401264640 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 401264640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (797344704).

401264640 is an abundant number, since it is smaller than the sum of its proper divisors (1193424768).

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

401264640 is a wasteful number, since it uses less digits than its factorization.

401264640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353 (or 328 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 401264640 is about 20031.5910501388. The cubic root of 401264640 is about 737.5819784386.

The spelling of 401264640 in words is "four hundred one million, two hundred sixty-four thousand, six hundred forty".