155697979 has 2 divisors, whose sum is σ = 155697980. Its totient is φ = 155697978.

The previous prime is 155697967. The next prime is 155698003. The reversal of 155697979 is 979796551.

It is a weak prime.

It is an emirp because it is prime and its reverse (979796551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155697979 - 2⁷ = 155697851 is a prime.

It is not a weakly prime, because it can be changed into another prime (155697379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77848989 + 77848990.

It is an arithmetic number, because the mean of its divisors is an integer number (77848990).

Almost surely, 2^155697979 is an apocalyptic number.

155697979 is a deficient number, since it is larger than the sum of its proper divisors (1).

155697979 is an equidigital number, since it uses as much as digits as its factorization.

155697979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5358150, while the sum is 58.

The square root of 155697979 is about 12477.8996229333. The cubic root of 155697979 is about 537.9736343680.

The spelling of 155697979 in words is "one hundred fifty-five million, six hundred ninety-seven thousand, nine hundred seventy-nine".