161631220431566 has 8 divisors (see below), whose sum is σ = 246065440060200. Its totient is φ = 79609407078168.

The previous prime is 161631220431559. The next prime is 161631220431679. The reversal of 161631220431566 is 665134022136161.

161631220431566 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×161631220431566² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161631220431566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 603101568641 + ... + 603101568908.

It is an arithmetic number, because the mean of its divisors is an integer number (30758180007525).

Almost surely, 2^{161631220431566} is an apocalyptic number.

161631220431566 is a deficient number, since it is larger than the sum of its proper divisors (84434219628634).

161631220431566 is a wasteful number, since it uses less digits than its factorization.

161631220431566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1206203137618.

The product of its (nonzero) digits is 933120, while the sum is 47.

The spelling of 161631220431566 in words is "one hundred sixty-one trillion, six hundred thirty-one billion, two hundred twenty million, four hundred thirty-one thousand, five hundred sixty-six".