22161881787 has 4 divisors (see below), whose sum is σ = 29549175720. Its totient is φ = 14774587856.

The previous prime is 22161881767. The next prime is 22161881869. The reversal of 22161881787 is 78718816122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 22161881787 - 2²² = 22157687483 is a prime.

It is a super-2 number, since 2×22161881787² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (22161881747) 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, 3693646962 + ... + 3693646967.

It is an arithmetic number, because the mean of its divisors is an integer number (7387293930).

Almost surely, 2^22161881787 is an apocalyptic number.

22161881787 is a deficient number, since it is larger than the sum of its proper divisors (7387293933).

22161881787 is an equidigital number, since it uses as much as digits as its factorization.

22161881787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7387293932.

The product of its digits is 602112, while the sum is 51.

The spelling of 22161881787 in words is "twenty-two billion, one hundred sixty-one million, eight hundred eighty-one thousand, seven hundred eighty-seven".