161171667621 has 16 divisors (see below), whose sum is σ = 238779022720. Its totient is φ = 107444996640.

The previous prime is 161171667571. The next prime is 161171667637. The reversal of 161171667621 is 126766171161.

161171667621 is a `hidden beast` number, since 1 + 6 + 1 + 1 + 7 + 16 + 6 + 7 + 621 = 666.

It is not a de Polignac number, because 161171667621 - 2¹⁰ = 161171666597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161171667121) 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, 2012481 + ... + 2091033.

It is an arithmetic number, because the mean of its divisors is an integer number (14923688920).

Almost surely, 2^161171667621 is an apocalyptic number.

It is an amenable number.

161171667621 is a deficient number, since it is larger than the sum of its proper divisors (77607355099).

161171667621 is an equidigital number, since it uses as much as digits as its factorization.

161171667621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154553 (or 154547 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The spelling of 161171667621 in words is "one hundred sixty-one billion, one hundred seventy-one million, six hundred sixty-seven thousand, six hundred twenty-one".