121540220415 has 32 divisors (see below), whose sum is σ = 218674794240. Its totient is φ = 64040463648.

The previous prime is 121540220387. The next prime is 121540220423. The reversal of 121540220415 is 514022045121.

It is a happy number.

121540220415 is a `hidden beast` number, since 1 + 21 + 5 + 4 + 0 + 220 + 415 = 666.

It is not a de Polignac number, because 121540220415 - 2⁷ = 121540220287 is a prime.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5412277 + ... + 5434686.

It is an arithmetic number, because the mean of its divisors is an integer number (6833587320).

Almost surely, 2^121540220415 is an apocalyptic number.

121540220415 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121540220415 is a deficient number, since it is larger than the sum of its proper divisors (97134573825).

121540220415 is a wasteful number, since it uses less digits than its factorization.

121540220415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10847060 (or 10847054 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

Adding to 121540220415 its reverse (514022045121), we get a palindrome (635562265536).

The spelling of 121540220415 in words is "one hundred twenty-one billion, five hundred forty million, two hundred twenty thousand, four hundred fifteen".