16329681 has 15 divisors (see below), whose sum is σ = 24448171. Its totient is φ = 10862208.

The previous prime is 16329623. The next prime is 16329689. The reversal of 16329681 is 18692361.

The square root of 16329681 is 4041.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 9979281 + 6350400 = 3159^2 + 2520^2 .

It is not a de Polignac number, because 16329681 - 2⁷ = 16329553 is a prime.

It is a super-2 number, since 2×16329681² = 533316963123522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16329689) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 36145 + ... + 36593.

Almost surely, 2^16329681 is an apocalyptic number.

16329681 is the 4041-st square number.

16329681 is the 2021-st centered octagonal number.

It is an amenable number.

16329681 is a deficient number, since it is larger than the sum of its proper divisors (8118490).

16329681 is an frugal number, since it uses more digits than its factorization.

16329681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910 (or 452 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The cubic root of 16329681 is about 253.7031738357.

Multiplying 16329681 by its sum of digits (36), we get a square (587868516 = 24246²).

The spelling of 16329681 in words is "sixteen million, three hundred twenty-nine thousand, six hundred eighty-one".