121561940 has 24 divisors (see below), whose sum is σ = 258878592. Its totient is φ = 47939360.

The previous prime is 121561933. The next prime is 121561949. The reversal of 121561940 is 49165121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121561949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41384 + ... + 44223.

It is an arithmetic number, because the mean of its divisors is an integer number (10786608).

Almost surely, 2^121561940 is an apocalyptic number.

121561940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121561940 is an abundant number, since it is smaller than the sum of its proper divisors (137316652).

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

121561940 is a wasteful number, since it uses less digits than its factorization.

121561940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85687 (or 85685 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 121561940 is about 11025.5131399858. The cubic root of 121561940 is about 495.3732382103.

The spelling of 121561940 in words is "one hundred twenty-one million, five hundred sixty-one thousand, nine hundred forty".