121989100 has 18 divisors (see below), whose sum is σ = 264716564. Its totient is φ = 48795600.

The previous prime is 121989097. The next prime is 121989103. The reversal of 121989100 is 1989121.

It is an interprime number because it is at equal distance from previous prime (121989097) and next prime (121989103).

It is not an unprimeable number, because it can be changed into a prime (121989103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 609846 + ... + 610045.

Almost surely, 2^121989100 is an apocalyptic number.

121989100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121989100 is an abundant number, since it is smaller than the sum of its proper divisors (142727464).

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

121989100 is a wasteful number, since it uses less digits than its factorization.

121989100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1219905 (or 1219898 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 121989100 is about 11044.8675863498. The cubic root of 121989100 is about 495.9527953255.

The spelling of 121989100 in words is "one hundred twenty-one million, nine hundred eighty-nine thousand, one hundred".