121561788 has 24 divisors (see below), whose sum is σ = 292794880. Its totient is φ = 39213360.

The previous prime is 121561721. The next prime is 121561789. The reversal of 121561788 is 887165121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121561789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 163018 + ... + 163761.

Almost surely, 2^121561788 is an apocalyptic number.

It is an amenable number.

121561788 is an abundant number, since it is smaller than the sum of its proper divisors (171233092).

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

121561788 is a wasteful number, since it uses less digits than its factorization.

121561788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326817 (or 326815 counting only the distinct ones).

The product of its digits is 26880, while the sum is 39.

The square root of 121561788 is about 11025.5062468805. The cubic root of 121561788 is about 495.3730317401.

The spelling of 121561788 in words is "one hundred twenty-one million, five hundred sixty-one thousand, seven hundred eighty-eight".