921661166129 has 12 divisors (see below), whose sum is σ = 1038928633200. Its totient is φ = 810845591400.

The previous prime is 921661166093. The next prime is 921661166141.

921661166129 is nontrivially palindromic in base 10.

It is a de Polignac number, because none of the positive numbers 2^k-921661166129 is a prime.

It is a super-4 number, since 4×921661166129⁴ (a number of 49 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921661166149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43583279 + ... + 43604420.

It is an arithmetic number, because the mean of its divisors is an integer number (86577386100).

Almost surely, 2^921661166129 is an apocalyptic number.

It is an amenable number.

921661166129 is a deficient number, since it is larger than the sum of its proper divisors (117267467071).

921661166129 is a wasteful number, since it uses less digits than its factorization.

921661166129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87187772 (or 87187741 counting only the distinct ones).

The product of its digits is 419904, while the sum is 50.

The spelling of 921661166129 in words is "nine hundred twenty-one billion, six hundred sixty-one million, one hundred sixty-six thousand, one hundred twenty-nine".