121605640 has 48 divisors (see below), whose sum is σ = 296295300. Its totient is φ = 44898048.

The previous prime is 121605637. The next prime is 121605703. The reversal of 121605640 is 46506121.

It can be written as a sum of positive squares in 6 ways, for example, as 24740676 + 96864964 = 4974^2 + 9842^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2235 + ... + 15754.

Almost surely, 2^121605640 is an apocalyptic number.

121605640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121605640 is an abundant number, since it is smaller than the sum of its proper divisors (174689660).

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

121605640 is a wasteful number, since it uses less digits than its factorization.

121605640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18026 (or 18009 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 121605640 is about 11027.4947290851. The cubic root of 121605640 is about 495.4325912638.

The spelling of 121605640 in words is "one hundred twenty-one million, six hundred five thousand, six hundred forty".