155909490161 has 2 divisors, whose sum is σ = 155909490162. Its totient is φ = 155909490160.

The previous prime is 155909490127. The next prime is 155909490169. The reversal of 155909490161 is 161094909551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 143579608561 + 12329881600 = 378919^2 + 111040^2 .

It is a cyclic number.

It is not a de Polignac number, because 155909490161 - 2¹⁴ = 155909473777 is a prime.

It is not a weakly prime, because it can be changed into another prime (155909490169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77954745080 + 77954745081.

It is an arithmetic number, because the mean of its divisors is an integer number (77954745081).

Almost surely, 2^155909490161 is an apocalyptic number.

It is an amenable number.

155909490161 is a deficient number, since it is larger than the sum of its proper divisors (1).

155909490161 is an equidigital number, since it uses as much as digits as its factorization.

155909490161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 437400, while the sum is 50.

The spelling of 155909490161 in words is "one hundred fifty-five billion, nine hundred nine million, four hundred ninety thousand, one hundred sixty-one".