40400640 has 288 divisors, whose sum is σ = 164828160. Its totient is φ = 9179136.

The previous prime is 40400603. The next prime is 40400713. The reversal of 40400640 is 4600404.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 241837 + ... + 242003.

It is an arithmetic number, because the mean of its divisors is an integer number (572320).

Almost surely, 2^40400640 is an apocalyptic number.

40400640 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 40400640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82414080).

40400640 is an abundant number, since it is smaller than the sum of its proper divisors (124427520).

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

40400640 is a wasteful number, since it uses less digits than its factorization.

40400640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 40400640 is about 6356.1497779709. The cubic root of 40400640 is about 343.1332062297.

The spelling of 40400640 in words is "forty million, four hundred thousand, six hundred forty".