121515771660 has 96 divisors (see below), whose sum is σ = 355220716032. Its totient is φ = 30979322880.

The previous prime is 121515771623. The next prime is 121515771719. The reversal of 121515771660 is 66177515121.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

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, 2775540 + ... + 2818980.

It is an arithmetic number, because the mean of its divisors is an integer number (3700215792).

Almost surely, 2^121515771660 is an apocalyptic number.

121515771660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121515771660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177610358016).

121515771660 is an abundant number, since it is smaller than the sum of its proper divisors (233704944372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121515771660 is a wasteful number, since it uses less digits than its factorization.

121515771660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45503 (or 45501 counting only the distinct ones).

The product of its (nonzero) digits is 88200, while the sum is 42.

The spelling of 121515771660 in words is "one hundred twenty-one billion, five hundred fifteen million, seven hundred seventy-one thousand, six hundred sixty".