121601557215 has 24 divisors (see below), whose sum is σ = 210800715840. Its totient is φ = 64846569024.

The previous prime is 121601557177. The next prime is 121601557271. The reversal of 121601557215 is 512755106121.

121601557215 is a `hidden beast` number, since 1 + 2 + 1 + 60 + 15 + 572 + 15 = 666.

It is not a de Polignac number, because 121601557215 - 2⁷ = 121601557087 is a prime.

It is a super-3 number, since 3×121601557215³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 121601557215.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 241401 + ... + 549069.

It is an arithmetic number, because the mean of its divisors is an integer number (8783363160).

Almost surely, 2^121601557215 is an apocalyptic number.

121601557215 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121601557215 is a deficient number, since it is larger than the sum of its proper divisors (89199158625).

121601557215 is a wasteful number, since it uses less digits than its factorization.

121601557215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316463 (or 316460 counting only the distinct ones).

The product of its (nonzero) digits is 21000, while the sum is 36.

The spelling of 121601557215 in words is "one hundred twenty-one billion, six hundred one million, five hundred fifty-seven thousand, two hundred fifteen".