155657297779 has 2 divisors, whose sum is σ = 155657297780. Its totient is φ = 155657297778.

The previous prime is 155657297773. The next prime is 155657297827. The reversal of 155657297779 is 977792756551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 155657297779 - 2³¹ = 153509814131 is a prime.

It is not a weakly prime, because it can be changed into another prime (155657297773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77828648889 + 77828648890.

It is an arithmetic number, because the mean of its divisors is an integer number (77828648890).

Almost surely, 2^155657297779 is an apocalyptic number.

155657297779 is a deficient number, since it is larger than the sum of its proper divisors (1).

155657297779 is an equidigital number, since it uses as much as digits as its factorization.

155657297779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 291721500, while the sum is 70.

The spelling of 155657297779 in words is "one hundred fifty-five billion, six hundred fifty-seven million, two hundred ninety-seven thousand, seven hundred seventy-nine".