16011161581 has 4 divisors (see below), whose sum is σ = 16037892000. Its totient is φ = 15984431164.

The previous prime is 16011161533. The next prime is 16011161627. The reversal of 16011161581 is 18516111061.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16011161581 is a prime.

It is a super-2 number, since 2×16011161581² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16011161501) 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, 13364311 + ... + 13365508.

It is an arithmetic number, because the mean of its divisors is an integer number (4009473000).

Almost surely, 2^16011161581 is an apocalyptic number.

It is an amenable number.

16011161581 is a deficient number, since it is larger than the sum of its proper divisors (26730419).

16011161581 is an equidigital number, since it uses as much as digits as its factorization.

16011161581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26730418.

The product of its (nonzero) digits is 1440, while the sum is 31.

The spelling of 16011161581 in words is "sixteen billion, eleven million, one hundred sixty-one thousand, five hundred eighty-one".