16161387861 has 4 divisors (see below), whose sum is σ = 21548517152. Its totient is φ = 10774258572.

The previous prime is 16161387839. The next prime is 16161387881. The reversal of 16161387861 is 16878316161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 16161387861 - 2⁵ = 16161387829 is a prime.

It is a super-2 number, since 2×16161387861² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16161387861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16161387811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2693564641 + ... + 2693564646.

It is an arithmetic number, because the mean of its divisors is an integer number (5387129288).

Almost surely, 2^16161387861 is an apocalyptic number.

It is an amenable number.

16161387861 is a deficient number, since it is larger than the sum of its proper divisors (5387129291).

16161387861 is an equidigital number, since it uses as much as digits as its factorization.

16161387861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5387129290.

The product of its digits is 290304, while the sum is 48.

The spelling of 16161387861 in words is "sixteen billion, one hundred sixty-one million, three hundred eighty-seven thousand, eight hundred sixty-one".