39791640 has 128 divisors (see below), whose sum is σ = 137871360. Its totient is φ = 8999424.

The previous prime is 39791639. The next prime is 39791659. The reversal of 39791640 is 4619793.

It is a super-2 number, since 2×39791640² = 3166749227779200, 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 31 ways as a sum of consecutive naturals, for example, 106494 + ... + 106866.

It is an arithmetic number, because the mean of its divisors is an integer number (1077120).

Almost surely, 2^39791640 is an apocalyptic number.

39791640 is a gapful number since it is divisible by the number (30) 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 39791640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68935680).

39791640 is an abundant number, since it is smaller than the sum of its proper divisors (98079720).

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

39791640 is a wasteful number, since it uses less digits than its factorization.

39791640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 39.

The square root of 39791640 is about 6308.0615088948. The cubic root of 39791640 is about 341.4003376287.

The spelling of 39791640 in words is "thirty-nine million, seven hundred ninety-one thousand, six hundred forty".