16556977 has 2 divisors, whose sum is σ = 16556978. Its totient is φ = 16556976.

The previous prime is 16556957. The next prime is 16556983. The reversal of 16556977 is 77965561.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9634816 + 6922161 = 3104^2 + 2631^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16556977 is a prime.

It is not a weakly prime, because it can be changed into another prime (16556927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278488 + 8278489.

It is an arithmetic number, because the mean of its divisors is an integer number (8278489).

Almost surely, 2^16556977 is an apocalyptic number.

It is an amenable number.

16556977 is a deficient number, since it is larger than the sum of its proper divisors (1).

16556977 is an equidigital number, since it uses as much as digits as its factorization.

16556977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 396900, while the sum is 46.

The square root of 16556977 is about 4069.0265420614. The cubic root of 16556977 is about 254.8748687619.

The spelling of 16556977 in words is "sixteen million, five hundred fifty-six thousand, nine hundred seventy-seven".