121561512 has 16 divisors (see below), whose sum is σ = 303903840. Its totient is φ = 40520496.

The previous prime is 121561499. The next prime is 121561513. The reversal of 121561512 is 215165121.

It is a super-2 number, since 2×121561512² = 29554402399452288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 5065063 = 121561512 / (1 + 2 + 1 + 5 + 6 + 1 + 5 + 1 + 2).

It is not an unprimeable number, because it can be changed into a prime (121561513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2532508 + ... + 2532555.

It is an arithmetic number, because the mean of its divisors is an integer number (18993990).

Almost surely, 2^121561512 is an apocalyptic number.

121561512 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

121561512 is an abundant number, since it is smaller than the sum of its proper divisors (182342328).

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

121561512 is a wasteful number, since it uses less digits than its factorization.

121561512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5065072 (or 5065068 counting only the distinct ones).

The product of its digits is 600, while the sum is 24.

The square root of 121561512 is about 11025.4937304413. The cubic root of 121561512 is about 495.3726568332.

The spelling of 121561512 in words is "one hundred twenty-one million, five hundred sixty-one thousand, five hundred twelve".