161721566192 has 40 divisors (see below), whose sum is σ = 313984167120. Its totient is φ = 80693544960.

The previous prime is 161721566183. The next prime is 161721566197. The reversal of 161721566192 is 291665127161.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161721566197) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25183142 + ... + 25189562.

It is an arithmetic number, because the mean of its divisors is an integer number (7849604178).

Almost surely, 2^161721566192 is an apocalyptic number.

It is an amenable number.

161721566192 is a deficient number, since it is larger than the sum of its proper divisors (152262600928).

161721566192 is a wasteful number, since it uses less digits than its factorization.

161721566192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9441 (or 9435 counting only the distinct ones).

The product of its digits is 272160, while the sum is 47.

The spelling of 161721566192 in words is "one hundred sixty-one billion, seven hundred twenty-one million, five hundred sixty-six thousand, one hundred ninety-two".