121638655 has 12 divisors (see below), whose sum is σ = 155059560. Its totient is φ = 91585664.

The previous prime is 121638641. The next prime is 121638667. The reversal of 121638655 is 556836121.

It is not a de Polignac number, because 121638655 - 2⁵ = 121638623 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40645 + ... + 43534.

It is an arithmetic number, because the mean of its divisors is an integer number (12921630).

Almost surely, 2^121638655 is an apocalyptic number.

121638655 is a deficient number, since it is larger than the sum of its proper divisors (33420905).

121638655 is an equidigital number, since it uses as much as digits as its factorization.

121638655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84218 (or 84201 counting only the distinct ones).

The product of its digits is 43200, while the sum is 37.

The square root of 121638655 is about 11028.9915676820. The cubic root of 121638655 is about 495.4774225918.

The spelling of 121638655 in words is "one hundred twenty-one million, six hundred thirty-eight thousand, six hundred fifty-five".