16677397881 has 21 divisors (see below), whose sum is σ = 25009887189. Its totient is φ = 11115940716.

The previous prime is 16677397879. The next prime is 16677397883. The reversal of 16677397881 is 18879377661.

The square root of 16677397881 is 129141.

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

16677397881 is a `hidden beast` number, since 166 + 7 + 7 + 397 + 8 + 81 = 666.

It is an interprime number because it is at equal distance from previous prime (16677397879) and next prime (16677397883).

It is not a de Polignac number, because 16677397881 - 2¹ = 16677397879 is a prime.

It is a super-2 number, since 2×16677397881² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16677397883) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 3484416 + ... + 3489198.

It is an arithmetic number, because the mean of its divisors is an integer number (1190947009).

Almost surely, 2^16677397881 is an apocalyptic number.

16677397881 is the 129141-st square number.

16677397881 is the 64571-st centered octagonal number.

It is an amenable number.

16677397881 is a deficient number, since it is larger than the sum of its proper divisors (8332489308).

16677397881 is an frugal number, since it uses more digits than its factorization.

16677397881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9584 (or 4786 counting only the distinct ones).

The product of its digits is 21337344, while the sum is 63.

The spelling of 16677397881 in words is "sixteen billion, six hundred seventy-seven million, three hundred ninety-seven thousand, eight hundred eighty-one".