161565505012 has 24 divisors (see below), whose sum is σ = 299501322120. Its totient is φ = 75997824000.

The previous prime is 161565505007. The next prime is 161565505109. The reversal of 161565505012 is 210505565161.

It can be written as a sum of positive squares in 4 ways, for example, as 38823185296 + 122742319716 = 197036^2 + 350346^2 .

It is a super-2 number, since 2×161565505012² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 357489 + ... + 671512.

It is an arithmetic number, because the mean of its divisors is an integer number (12479221755).

Almost surely, 2^161565505012 is an apocalyptic number.

It is an amenable number.

161565505012 is a deficient number, since it is larger than the sum of its proper divisors (137935817108).

161565505012 is a wasteful number, since it uses less digits than its factorization.

161565505012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1031331 (or 1031329 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 37.

The spelling of 161565505012 in words is "one hundred sixty-one billion, five hundred sixty-five million, five hundred five thousand, twelve".