161561061516 has 24 divisors (see below), whose sum is σ = 396816642880. Its totient is φ = 51019282512.

The previous prime is 161561061511. The next prime is 161561061547. The reversal of 161561061516 is 615160165161.

It is a super-2 number, since 2×161561061516² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161561061511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 354300346 + ... + 354300801.

Almost surely, 2^161561061516 is an apocalyptic number.

It is an amenable number.

161561061516 is an abundant number, since it is smaller than the sum of its proper divisors (235255581364).

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

161561061516 is a wasteful number, since it uses less digits than its factorization.

161561061516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708601173 (or 708601171 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 39.

The spelling of 161561061516 in words is "one hundred sixty-one billion, five hundred sixty-one million, sixty-one thousand, five hundred sixteen".