166521616 has 10 divisors (see below), whose sum is σ = 322635662. Its totient is φ = 83260800.

The previous prime is 166521533. The next prime is 166521617. The reversal of 166521616 is 616125661.

It is a happy number.

166521616 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 95961616 + 70560000 = 9796^2 + 8400^2 .

It is not an unprimeable number, because it can be changed into a prime (166521617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5203785 + ... + 5203816.

Almost surely, 2^166521616 is an apocalyptic number.

166521616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

166521616 is a deficient number, since it is larger than the sum of its proper divisors (156114046).

166521616 is a wasteful number, since it uses less digits than its factorization.

166521616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10407609 (or 10407603 counting only the distinct ones).

The product of its digits is 12960, while the sum is 34.

The square root of 166521616 is about 12904.3254763664. The cubic root of 166521616 is about 550.1615128961.

The spelling of 166521616 in words is "one hundred sixty-six million, five hundred twenty-one thousand, six hundred sixteen".