166587150601581 has 16 divisors (see below), whose sum is σ = 222300926983488. Its totient is φ = 110965741488000.

The previous prime is 166587150601577. The next prime is 166587150601591. The reversal of 166587150601581 is 185106051785661.

It is not a de Polignac number, because 166587150601581 - 2² = 166587150601577 is a prime.

It is a super-2 number, since 2×166587150601581² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166587150601591) 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, 166388281 + ... + 167386481.

It is an arithmetic number, because the mean of its divisors is an integer number (13893807936468).

Almost surely, 2^{166587150601581} is an apocalyptic number.

It is an amenable number.

166587150601581 is a deficient number, since it is larger than the sum of its proper divisors (55713776381907).

166587150601581 is a wasteful number, since it uses less digits than its factorization.

166587150601581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1044412.

The product of its (nonzero) digits is 12096000, while the sum is 60.

The spelling of 166587150601581 in words is "one hundred sixty-six trillion, five hundred eighty-seven billion, one hundred fifty million, six hundred one thousand, five hundred eighty-one".