161651219568 has 20 divisors (see below), whose sum is σ = 417598984008. Its totient is φ = 53883739840.

The previous prime is 161651219531. The next prime is 161651219591. The reversal of 161651219568 is 865912156161.

It is a super-2 number, since 2×161651219568² (a number of 23 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 161651219568.

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, 1683866823 + ... + 1683866918.

Almost surely, 2^161651219568 is an apocalyptic number.

It is an amenable number.

161651219568 is an abundant number, since it is smaller than the sum of its proper divisors (255947764440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161651219568 is a wasteful number, since it uses less digits than its factorization.

161651219568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3367733752 (or 3367733746 counting only the distinct ones).

The product of its digits is 777600, while the sum is 51.

The spelling of 161651219568 in words is "one hundred sixty-one billion, six hundred fifty-one million, two hundred nineteen thousand, five hundred sixty-eight".