401600640 has 128 divisors (see below), whose sum is σ = 1463022720. Its totient is φ = 91791360.

The previous prime is 401600623. The next prime is 401600651. The reversal of 401600640 is 46006104.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×401600640² = 322566148096819200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1501 + ... + 28380.

It is an arithmetic number, because the mean of its divisors is an integer number (11429865).

Almost surely, 2^401600640 is an apocalyptic number.

401600640 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 401600640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (731511360).

401600640 is an abundant number, since it is smaller than the sum of its proper divisors (1061422080).

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

401600640 is a wasteful number, since it uses less digits than its factorization.

401600640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29910 (or 29898 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 401600640 is about 20039.9760478899. The cubic root of 401600640 is about 737.7877930717.

Adding to 401600640 its reverse (46006104), we get a palindrome (447606744).

The spelling of 401600640 in words is "four hundred one million, six hundred thousand, six hundred forty".