39830921 has 4 divisors (see below), whose sum is σ = 42894852. Its totient is φ = 36766992.

The previous prime is 39830873. The next prime is 39830927. The reversal of 39830921 is 12903893.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1836025 + 37994896 = 1355^2 + 6164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39830921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (39830927) 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, 1531946 + ... + 1531971.

It is an arithmetic number, because the mean of its divisors is an integer number (10723713).

Almost surely, 2^39830921 is an apocalyptic number.

It is an amenable number.

39830921 is a deficient number, since it is larger than the sum of its proper divisors (3063931).

39830921 is a wasteful number, since it uses less digits than its factorization.

39830921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3063930.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 39830921 is about 6311.1742964364. The cubic root of 39830921 is about 341.5126404161.

The spelling of 39830921 in words is "thirty-nine million, eight hundred thirty thousand, nine hundred twenty-one".