155969971 has 2 divisors, whose sum is σ = 155969972. Its totient is φ = 155969970.

The previous prime is 155969963. The next prime is 155969977. The reversal of 155969971 is 179969551.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 155969971 - 2³ = 155969963 is a prime.

It is not a weakly prime, because it can be changed into another prime (155969977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77984985 + 77984986.

It is an arithmetic number, because the mean of its divisors is an integer number (77984986).

Almost surely, 2^155969971 is an apocalyptic number.

155969971 is a deficient number, since it is larger than the sum of its proper divisors (1).

155969971 is an equidigital number, since it uses as much as digits as its factorization.

155969971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 765450, while the sum is 52.

The square root of 155969971 is about 12488.7938168584. The cubic root of 155969971 is about 538.2867178615.

The spelling of 155969971 in words is "one hundred fifty-five million, nine hundred sixty-nine thousand, nine hundred seventy-one".