155121647 has 2 divisors, whose sum is σ = 155121648. Its totient is φ = 155121646.

The previous prime is 155121611. The next prime is 155121671. The reversal of 155121647 is 746121551.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 155121647 - 2¹² = 155117551 is a prime.

It is a Chen prime.

It is equal to p_8716028 and since 155121647 and 8716028 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155121607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77560823 + 77560824.

It is an arithmetic number, because the mean of its divisors is an integer number (77560824).

Almost surely, 2^155121647 is an apocalyptic number.

155121647 is a deficient number, since it is larger than the sum of its proper divisors (1).

155121647 is an equidigital number, since it uses as much as digits as its factorization.

155121647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8400, while the sum is 32.

The square root of 155121647 is about 12454.7841008987. The cubic root of 155121647 is about 537.3090255023.

The spelling of 155121647 in words is "one hundred fifty-five million, one hundred twenty-one thousand, six hundred forty-seven".