155149609 has 2 divisors, whose sum is σ = 155149610. Its totient is φ = 155149608.

The previous prime is 155149607. The next prime is 155149661. The reversal of 155149609 is 906941551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84640000 + 70509609 = 9200^2 + 8397^2 .

It is a cyclic number.

It is not a de Polignac number, because 155149609 - 2¹ = 155149607 is a prime.

Together with 155149607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (155149607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77574804 + 77574805.

It is an arithmetic number, because the mean of its divisors is an integer number (77574805).

Almost surely, 2^155149609 is an apocalyptic number.

It is an amenable number.

155149609 is a deficient number, since it is larger than the sum of its proper divisors (1).

155149609 is an equidigital number, since it uses as much as digits as its factorization.

155149609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48600, while the sum is 40.

The square root of 155149609 is about 12455.9065908508. The cubic root of 155149609 is about 537.3413084076.

The spelling of 155149609 in words is "one hundred fifty-five million, one hundred forty-nine thousand, six hundred nine".