166117823620987 has 16 divisors (see below), whose sum is σ = 199911531688960. Its totient is φ = 134845053720192.

The previous prime is 166117823620951. The next prime is 166117823621023. The reversal of 166117823620987 is 789026328711661.

It is an interprime number because it is at equal distance from previous prime (166117823620951) and next prime (166117823621023).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166117823620987 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166117823620907) 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, 220062003 + ... + 220815580.

It is an arithmetic number, because the mean of its divisors is an integer number (12494470730560).

Almost surely, 2^{166117823620987} is an apocalyptic number.

166117823620987 is a deficient number, since it is larger than the sum of its proper divisors (33793708067973).

166117823620987 is a wasteful number, since it uses less digits than its factorization.

166117823620987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440880442.

The product of its (nonzero) digits is 73156608, while the sum is 67.

The spelling of 166117823620987 in words is "one hundred sixty-six trillion, one hundred seventeen billion, eight hundred twenty-three million, six hundred twenty thousand, nine hundred eighty-seven".