16521172 has 6 divisors (see below), whose sum is σ = 28912058. Its totient is φ = 8260584.

The previous prime is 16521157. The next prime is 16521187. The reversal of 16521172 is 27112561.

It is an interprime number because it is at equal distance from previous prime (16521157) and next prime (16521187).

It can be written as a sum of positive squares in only one way, i.e., 10150596 + 6370576 = 3186^2 + 2524^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2065143 + ... + 2065150.

Almost surely, 2^16521172 is an apocalyptic number.

It is an amenable number.

16521172 is a deficient number, since it is larger than the sum of its proper divisors (12390886).

16521172 is a wasteful number, since it uses less digits than its factorization.

16521172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4130297 (or 4130295 counting only the distinct ones).

The product of its digits is 840, while the sum is 25.

The square root of 16521172 is about 4064.6244598979. The cubic root of 16521172 is about 254.6910111075.

The spelling of 16521172 in words is "sixteen million, five hundred twenty-one thousand, one hundred seventy-two".