21870672231 has 4 divisors (see below), whose sum is σ = 29160896312. Its totient is φ = 14580448152.

The previous prime is 21870672223. The next prime is 21870672259. The reversal of 21870672231 is 13227607812.

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

It is not a de Polignac number, because 21870672231 - 2³ = 21870672223 is a prime.

It is a super-2 number, since 2×21870672231² (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 21870672231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21870672281) 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, 3645112036 + ... + 3645112041.

It is an arithmetic number, because the mean of its divisors is an integer number (7290224078).

Almost surely, 2^21870672231 is an apocalyptic number.

21870672231 is a deficient number, since it is larger than the sum of its proper divisors (7290224081).

21870672231 is an equidigital number, since it uses as much as digits as its factorization.

21870672231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7290224080.

The product of its (nonzero) digits is 56448, while the sum is 39.

The spelling of 21870672231 in words is "twenty-one billion, eight hundred seventy million, six hundred seventy-two thousand, two hundred thirty-one".