39677921 has 4 divisors (see below), whose sum is σ = 41403072. Its totient is φ = 37952772.

The previous prime is 39677899. The next prime is 39677927. The reversal of 39677921 is 12977693.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12977693 = 1087 ⋅11939.

It is a cyclic number.

It is not a de Polignac number, because 39677921 - 2⁶ = 39677857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39677927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 862541 + ... + 862586.

It is an arithmetic number, because the mean of its divisors is an integer number (10350768).

Almost surely, 2^39677921 is an apocalyptic number.

It is an amenable number.

39677921 is a deficient number, since it is larger than the sum of its proper divisors (1725151).

39677921 is a wasteful number, since it uses less digits than its factorization.

39677921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1725150.

The product of its digits is 142884, while the sum is 44.

The square root of 39677921 is about 6299.0412762578. The cubic root of 39677921 is about 341.0748023480.

The spelling of 39677921 in words is "thirty-nine million, six hundred seventy-seven thousand, nine hundred twenty-one".