16939521 has 6 divisors (see below), whose sum is σ = 24468210. Its totient is φ = 11293008.

The previous prime is 16939501. The next prime is 16939537. The reversal of 16939521 is 12593961.

It can be written as a sum of positive squares in only one way, i.e., 13838400 + 3101121 = 3720^2 + 1761^2 .

It is not a de Polignac number, because 16939521 - 2⁶ = 16939457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16939501) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 941076 + ... + 941093.

It is an arithmetic number, because the mean of its divisors is an integer number (4078035).

Almost surely, 2^16939521 is an apocalyptic number.

It is an amenable number.

16939521 is a deficient number, since it is larger than the sum of its proper divisors (7528689).

16939521 is a wasteful number, since it uses less digits than its factorization.

16939521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1882175 (or 1882172 counting only the distinct ones).

The product of its digits is 14580, while the sum is 36.

The square root of 16939521 is about 4115.7649349787. The cubic root of 16939521 is about 256.8228780532.

The spelling of 16939521 in words is "sixteen million, nine hundred thirty-nine thousand, five hundred twenty-one".