155561051 has 2 divisors, whose sum is σ = 155561052. Its totient is φ = 155561050.

The previous prime is 155561027. The next prime is 155561083. The reversal of 155561051 is 150165551.

It is a happy number.

155561051 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 155561051 - 2¹⁸ = 155298907 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (155561251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77780525 + 77780526.

It is an arithmetic number, because the mean of its divisors is an integer number (77780526).

Almost surely, 2^155561051 is an apocalyptic number.

155561051 is a deficient number, since it is larger than the sum of its proper divisors (1).

155561051 is an equidigital number, since it uses as much as digits as its factorization.

155561051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3750, while the sum is 29.

The square root of 155561051 is about 12472.4115951968. The cubic root of 155561051 is about 537.8158818199.

The spelling of 155561051 in words is "one hundred fifty-five million, five hundred sixty-one thousand, fifty-one".