39897920 has 56 divisors (see below), whose sum is σ = 97356168. Its totient is φ = 15564800.

The previous prime is 39897917. The next prime is 39897947. The reversal of 39897920 is 2979893.

It can be written as a sum of positive squares in 4 ways, for example, as 4946176 + 34951744 = 2224^2 + 5912^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11600 + ... + 14640.

It is an arithmetic number, because the mean of its divisors is an integer number (1738503).

Almost surely, 2^39897920 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 39897920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48678084).

39897920 is an abundant number, since it is smaller than the sum of its proper divisors (57458248).

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

39897920 is a wasteful number, since it uses less digits than its factorization.

39897920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3099 (or 3089 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 47.

The square root of 39897920 is about 6316.4800324231. The cubic root of 39897920 is about 341.7040175969.

The spelling of 39897920 in words is "thirty-nine million, eight hundred ninety-seven thousand, nine hundred twenty".