66121312163640 has 32 divisors (see below), whose sum is σ = 198363936491280. Its totient is φ = 17632349910272.

The previous prime is 66121312163623. The next prime is 66121312163681. The reversal of 66121312163640 is 4636121312166.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 66121312163592 and 66121312163601.

It is a congruent number.

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, 275505467229 + ... + 275505467468.

Almost surely, 2^{66121312163640} is an apocalyptic number.

66121312163640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66121312163640 is an abundant number, since it is smaller than the sum of its proper divisors (132242624327640).

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

66121312163640 is a wasteful number, since it uses less digits than its factorization.

66121312163640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551010934711 (or 551010934707 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 42.

The spelling of 66121312163640 in words is "sixty-six trillion, one hundred twenty-one billion, three hundred twelve million, one hundred sixty-three thousand, six hundred forty".