121661000 has 32 divisors (see below), whose sum is σ = 284689080. Its totient is φ = 48664000.

The previous prime is 121660999. The next prime is 121661011. The reversal of 121661000 is 166121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 43903876 + 77757124 = 6626^2 + 8818^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 121661000.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59831 + ... + 61830.

Almost surely, 2^121661000 is an apocalyptic number.

121661000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121661000 is an abundant number, since it is smaller than the sum of its proper divisors (163028080).

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

121661000 is a wasteful number, since it uses less digits than its factorization.

121661000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121682 (or 121668 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 121661000 is about 11030.0045330906. The cubic root of 121661000 is about 495.5077604400.

The spelling of 121661000 in words is "one hundred twenty-one million, six hundred sixty-one thousand".