21715253283 has 4 divisors (see below), whose sum is σ = 28953671048. Its totient is φ = 14476835520.

The previous prime is 21715253267. The next prime is 21715253291. The reversal of 21715253283 is 38235251712.

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

It is not a de Polignac number, because 21715253283 - 2⁴ = 21715253267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21715253233) 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, 3619208878 + ... + 3619208883.

It is an arithmetic number, because the mean of its divisors is an integer number (7238417762).

Almost surely, 2^21715253283 is an apocalyptic number.

21715253283 is a deficient number, since it is larger than the sum of its proper divisors (7238417765).

21715253283 is an equidigital number, since it uses as much as digits as its factorization.

21715253283 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7238417764.

The product of its digits is 100800, while the sum is 39.

The spelling of 21715253283 in words is "twenty-one billion, seven hundred fifteen million, two hundred fifty-three thousand, two hundred eighty-three".