39920661 has 32 divisors (see below), whose sum is σ = 65049600. Its totient is φ = 23995440.

The previous prime is 39920651. The next prime is 39920687. The reversal of 39920661 is 16602993.

39920661 is a `hidden beast` number, since 399 + 206 + 61 = 666.

It is not a de Polignac number, because 39920661 - 2⁶ = 39920597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39920611) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 40800 + ... + 41766.

It is an arithmetic number, because the mean of its divisors is an integer number (2032800).

Almost surely, 2^39920661 is an apocalyptic number.

It is an amenable number.

39920661 is a deficient number, since it is larger than the sum of its proper divisors (25128939).

39920661 is a wasteful number, since it uses less digits than its factorization.

39920661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1126 (or 1120 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 39920661 is about 6318.2799083295. The cubic root of 39920661 is about 341.7689267045.

The spelling of 39920661 in words is "thirty-nine million, nine hundred twenty thousand, six hundred sixty-one".