161631817653 has 16 divisors (see below), whose sum is σ = 217591934976. Its totient is φ = 106718094960.

The previous prime is 161631817603. The next prime is 161631817657. The reversal of 161631817653 is 356718136161.

It is not a de Polignac number, because 161631817653 - 2⁹ = 161631817141 is a prime.

It is a super-2 number, since 2×161631817653² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161631817657) 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, 491251 + ... + 751392.

It is an arithmetic number, because the mean of its divisors is an integer number (13599495936).

Almost surely, 2^161631817653 is an apocalyptic number.

It is an amenable number.

161631817653 is a deficient number, since it is larger than the sum of its proper divisors (55960117323).

161631817653 is a wasteful number, since it uses less digits than its factorization.

161631817653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1243064.

The product of its digits is 544320, while the sum is 48.

The spelling of 161631817653 in words is "one hundred sixty-one billion, six hundred thirty-one million, eight hundred seventeen thousand, six hundred fifty-three".