155649121 has 24 divisors (see below), whose sum is σ = 173272704. Its totient is φ = 139618080.

The previous prime is 155649113. The next prime is 155649149. The reversal of 155649121 is 121946551.

It is a happy number.

It is not a de Polignac number, because 155649121 - 2³ = 155649113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (155649191) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 574216 + ... + 574486.

It is an arithmetic number, because the mean of its divisors is an integer number (7219696).

Almost surely, 2^155649121 is an apocalyptic number.

It is an amenable number.

155649121 is a deficient number, since it is larger than the sum of its proper divisors (17623583).

155649121 is a wasteful number, since it uses less digits than its factorization.

155649121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389 (or 370 counting only the distinct ones).

The product of its digits is 10800, while the sum is 34.

The square root of 155649121 is about 12475.9416879048. The cubic root of 155649121 is about 537.9173564685.

The spelling of 155649121 in words is "one hundred fifty-five million, six hundred forty-nine thousand, one hundred twenty-one".