16956987961 has 9 divisors (see below), whose sum is σ = 17131021999. Its totient is φ = 16784708224.

The previous prime is 16956987959. The next prime is 16956987979. The reversal of 16956987961 is 16978965961.

The square root of 16956987961 is 130219.

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., 5690439225 + 11266548736 = 75435^2 + 106144^2 .

It is not a de Polignac number, because 16956987961 - 2¹ = 16956987959 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16956987661) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 13932825 + ... + 13934041.

Almost surely, 2^16956987961 is an apocalyptic number.

16956987961 is the 130219-th square number.

16956987961 is the 65110-th centered octagonal number.

It is an amenable number.

16956987961 is a deficient number, since it is larger than the sum of its proper divisors (174034038).

16956987961 is an frugal number, since it uses more digits than its factorization.

16956987961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2648 (or 1324 counting only the distinct ones).

The product of its digits is 44089920, while the sum is 67.

The spelling of 16956987961 in words is "sixteen billion, nine hundred fifty-six million, nine hundred eighty-seven thousand, nine hundred sixty-one".