39665920 has 144 divisors (see below), whose sum is σ = 114791040. Its totient is φ = 12828672.

The previous prime is 39665897. The next prime is 39665929. The reversal of 39665920 is 2956693.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (39665929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 170124 + ... + 170356.

It is an arithmetic number, because the mean of its divisors is an integer number (797160).

Almost surely, 2^39665920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 39665920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57395520).

39665920 is an abundant number, since it is smaller than the sum of its proper divisors (75125120).

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

39665920 is a wasteful number, since it uses less digits than its factorization.

39665920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 266 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 40.

The square root of 39665920 is about 6298.0885989322. The cubic root of 39665920 is about 341.0404116731.

The spelling of 39665920 in words is "thirty-nine million, six hundred sixty-five thousand, nine hundred twenty".