40640638 has 8 divisors (see below), whose sum is σ = 61011720. Its totient is φ = 20303400.

The previous prime is 40640623. The next prime is 40640647. The reversal of 40640638 is 83604604.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×40640638² = 3303322914094088, 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 3 ways as a sum of consecutive naturals, for example, 5208 + ... + 10411.

It is an arithmetic number, because the mean of its divisors is an integer number (7626465).

Almost surely, 2^40640638 is an apocalyptic number.

40640638 is a deficient number, since it is larger than the sum of its proper divisors (20371082).

40640638 is a wasteful number, since it uses less digits than its factorization.

40640638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16922.

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 40640638 is about 6375.0010196078. The cubic root of 40640638 is about 343.8113204986.

The spelling of 40640638 in words is "forty million, six hundred forty thousand, six hundred thirty-eight".