39938640 has 80 divisors (see below), whose sum is σ = 141502848. Its totient is φ = 9128448.

The previous prime is 39938629. The next prime is 39938653. The reversal of 39938640 is 4683993.

39938640 = 765² + 766² + ... + 827².

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 39938592 and 39938601.

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, 10207 + ... + 13566.

Almost surely, 2^39938640 is an apocalyptic number.

39938640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

39938640 is an abundant number, since it is smaller than the sum of its proper divisors (101564208).

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

39938640 is a wasteful number, since it uses less digits than its factorization.

39938640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23796 (or 23790 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 42.

The square root of 39938640 is about 6319.7025246447. The cubic root of 39938640 is about 341.8202263002.

The spelling of 39938640 in words is "thirty-nine million, nine hundred thirty-eight thousand, six hundred forty".