155667973 has 2 divisors, whose sum is σ = 155667974. Its totient is φ = 155667972.

The previous prime is 155667971. The next prime is 155667983. The reversal of 155667973 is 379766551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154306084 + 1361889 = 12422^2 + 1167^2 .

It is a cyclic number.

It is not a de Polignac number, because 155667973 - 2¹ = 155667971 is a prime.

Together with 155667971, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155667971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77833986 + 77833987.

It is an arithmetic number, because the mean of its divisors is an integer number (77833987).

Almost surely, 2^155667973 is an apocalyptic number.

It is an amenable number.

155667973 is a deficient number, since it is larger than the sum of its proper divisors (1).

155667973 is an equidigital number, since it uses as much as digits as its factorization.

155667973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1190700, while the sum is 49.

The square root of 155667973 is about 12476.6971991790. The cubic root of 155667973 is about 537.9390728533.

The spelling of 155667973 in words is "one hundred fifty-five million, six hundred sixty-seven thousand, nine hundred seventy-three".