161557051 has 2 divisors, whose sum is σ = 161557052. Its totient is φ = 161557050.

The previous prime is 161557043. The next prime is 161557127. The reversal of 161557051 is 150755161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161557051 - 2³ = 161557043 is a prime.

It is a super-2 number, since 2×161557051² = 52201361455633202, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161557351) 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, 80778525 + 80778526.

It is an arithmetic number, because the mean of its divisors is an integer number (80778526).

Almost surely, 2^161557051 is an apocalyptic number.

161557051 is a deficient number, since it is larger than the sum of its proper divisors (1).

161557051 is an equidigital number, since it uses as much as digits as its factorization.

161557051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5250, while the sum is 31.

The square root of 161557051 is about 12710.5094705130. The cubic root of 161557051 is about 544.6388775667.

The spelling of 161557051 in words is "one hundred sixty-one million, five hundred fifty-seven thousand, fifty-one".