21872182313 has 4 divisors (see below), whose sum is σ = 21872767188. Its totient is φ = 21871597440.

The previous prime is 21872182289. The next prime is 21872182351. The reversal of 21872182313 is 31328127812.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17868203584 + 4003978729 = 133672^2 + 63277^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21872182313 is a prime.

It is a super-2 number, since 2×21872182313² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21872182513) 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, 232208 + ... + 312513.

It is an arithmetic number, because the mean of its divisors is an integer number (5468191797).

Almost surely, 2^21872182313 is an apocalyptic number.

It is an amenable number.

21872182313 is a deficient number, since it is larger than the sum of its proper divisors (584875).

21872182313 is an equidigital number, since it uses as much as digits as its factorization.

21872182313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 584874.

The product of its digits is 32256, while the sum is 38.

The spelling of 21872182313 in words is "twenty-one billion, eight hundred seventy-two million, one hundred eighty-two thousand, three hundred thirteen".