121857664020 has 48 divisors (see below), whose sum is σ = 341832236928. Its totient is φ = 32435303040.

The previous prime is 121857664007. The next prime is 121857664021. The reversal of 121857664020 is 20466758121.

It is a happy number.

It is a super-2 number, since 2×121857664020² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121857664021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1844584 + ... + 1909503.

It is an arithmetic number, because the mean of its divisors is an integer number (7121504936).

Almost surely, 2^121857664020 is an apocalyptic number.

121857664020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121857664020 is an abundant number, since it is smaller than the sum of its proper divisors (219974572908).

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

121857664020 is a wasteful number, since it uses less digits than its factorization.

121857664020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3754640 (or 3754638 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 42.

The spelling of 121857664020 in words is "one hundred twenty-one billion, eight hundred fifty-seven million, six hundred sixty-four thousand, twenty".