121615155 has 32 divisors (see below), whose sum is σ = 216691200. Its totient is φ = 64715616.

The previous prime is 121615147. The next prime is 121615157. The reversal of 121615155 is 551516121.

It is not a de Polignac number, because 121615155 - 2³ = 121615147 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (121615157) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 88282 + ... + 89648.

It is an arithmetic number, because the mean of its divisors is an integer number (6771600).

Almost surely, 2^121615155 is an apocalyptic number.

121615155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121615155 is a deficient number, since it is larger than the sum of its proper divisors (95076045).

121615155 is a wasteful number, since it uses less digits than its factorization.

121615155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2040 (or 2034 counting only the distinct ones).

The product of its digits is 1500, while the sum is 27.

The square root of 121615155 is about 11027.9261422989. The cubic root of 121615155 is about 495.4455125893.

The spelling of 121615155 in words is "one hundred twenty-one million, six hundred fifteen thousand, one hundred fifty-five".