155418961 has 2 divisors, whose sum is σ = 155418962. Its totient is φ = 155418960.

The previous prime is 155418959. The next prime is 155418973. The reversal of 155418961 is 169814551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145926400 + 9492561 = 12080^2 + 3081^2 .

It is a cyclic number.

It is not a de Polignac number, because 155418961 - 2¹ = 155418959 is a prime.

Together with 155418959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (155418931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77709480 + 77709481.

It is an arithmetic number, because the mean of its divisors is an integer number (77709481).

Almost surely, 2^155418961 is an apocalyptic number.

It is an amenable number.

155418961 is a deficient number, since it is larger than the sum of its proper divisors (1).

155418961 is an equidigital number, since it uses as much as digits as its factorization.

155418961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43200, while the sum is 40.

The square root of 155418961 is about 12466.7141220131. The cubic root of 155418961 is about 537.6520843122.

The spelling of 155418961 in words is "one hundred fifty-five million, four hundred eighteen thousand, nine hundred sixty-one".