121240405022155 has 72 divisors (see below), whose sum is σ = 161710169699232. Its totient is φ = 87237697468416.

The previous prime is 121240405022083. The next prime is 121240405022179. The reversal of 121240405022155 is 551220504042121.

It is not a de Polignac number, because 121240405022155 - 2⁷ = 121240405022027 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121240405022155.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 838479994 + ... + 838624576.

It is an arithmetic number, because the mean of its divisors is an integer number (2245974579156).

Almost surely, 2^{121240405022155} is an apocalyptic number.

121240405022155 is a deficient number, since it is larger than the sum of its proper divisors (40469764677077).

121240405022155 is a wasteful number, since it uses less digits than its factorization.

121240405022155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145765 (or 145725 counting only the distinct ones).

The product of its (nonzero) digits is 32000, while the sum is 34.

Adding to 121240405022155 its reverse (551220504042121), we get a palindrome (672460909064276).

The spelling of 121240405022155 in words is "one hundred twenty-one trillion, two hundred forty billion, four hundred five million, twenty-two thousand, one hundred fifty-five".