121599940 has 72 divisors (see below), whose sum is σ = 319507776. Its totient is φ = 37766400.

The previous prime is 121599913. The next prime is 121599979. The reversal of 121599940 is 49995121.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 121599893 and 121599902.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 432600 + ... + 432880.

It is an arithmetic number, because the mean of its divisors is an integer number (4437608).

Almost surely, 2^121599940 is an apocalyptic number.

121599940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121599940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159753888).

121599940 is an abundant number, since it is smaller than the sum of its proper divisors (197907836).

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

121599940 is a wasteful number, since it uses less digits than its factorization.

121599940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589 (or 306 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 40.

The square root of 121599940 is about 11027.2362811359. The cubic root of 121599940 is about 495.4248503677.

The spelling of 121599940 in words is "one hundred twenty-one million, five hundred ninety-nine thousand, nine hundred forty".