16218977 has 2 divisors, whose sum is σ = 16218978. Its totient is φ = 16218976.

The previous prime is 16218971. The next prime is 16218991. The reversal of 16218977 is 77981261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9541921 + 6677056 = 3089^2 + 2584^2 .

It is a cyclic number.

It is not a de Polignac number, because 16218977 - 2²⁰ = 15170401 is a prime.

It is not a weakly prime, because it can be changed into another prime (16218971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8109488 + 8109489.

It is an arithmetic number, because the mean of its divisors is an integer number (8109489).

Almost surely, 2^16218977 is an apocalyptic number.

It is an amenable number.

16218977 is a deficient number, since it is larger than the sum of its proper divisors (1).

16218977 is an equidigital number, since it uses as much as digits as its factorization.

16218977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 41.

The square root of 16218977 is about 4027.2791062950. The cubic root of 16218977 is about 253.1285624048.

The spelling of 16218977 in words is "sixteen million, two hundred eighteen thousand, nine hundred seventy-seven".