66172166442840 has 32 divisors (see below), whose sum is σ = 198516499328880. Its totient is φ = 17645911051392.

The previous prime is 66172166442839. The next prime is 66172166442857. The reversal of 66172166442840 is 4824466127166.

It is a super-2 number, since 2×66172166442840² (a number of 28 digits) contains 22 as substring.

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, 275717360059 + ... + 275717360298.

Almost surely, 2^{66172166442840} is an apocalyptic number.

66172166442840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66172166442840 is an abundant number, since it is smaller than the sum of its proper divisors (132344332886040).

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

66172166442840 is a wasteful number, since it uses less digits than its factorization.

66172166442840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551434720371 (or 551434720367 counting only the distinct ones).

The product of its (nonzero) digits is 18579456, while the sum is 57.

The spelling of 66172166442840 in words is "sixty-six trillion, one hundred seventy-two billion, one hundred sixty-six million, four hundred forty-two thousand, eight hundred forty".