16556377 has 2 divisors, whose sum is σ = 16556378. Its totient is φ = 16556376.

The previous prime is 16556369. The next prime is 16556381. The reversal of 16556377 is 77365561.

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., 13111641 + 3444736 = 3621^2 + 1856^2 .

It is a cyclic number.

It is not a de Polignac number, because 16556377 - 2³ = 16556369 is a prime.

It is a super-2 number, since 2×16556377² = 548227238732258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16556357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278188 + 8278189.

It is an arithmetic number, because the mean of its divisors is an integer number (8278189).

Almost surely, 2^16556377 is an apocalyptic number.

It is an amenable number.

16556377 is a deficient number, since it is larger than the sum of its proper divisors (1).

16556377 is an equidigital number, since it uses as much as digits as its factorization.

16556377 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 132300, while the sum is 40.

The square root of 16556377 is about 4068.9528136856. The cubic root of 16556377 is about 254.8717899638.

The spelling of 16556377 in words is "sixteen million, five hundred fifty-six thousand, three hundred seventy-seven".