21750265217 has 4 divisors (see below), whose sum is σ = 22118913840. Its totient is φ = 21381616596.

The previous prime is 21750265189. The next prime is 21750265319. The reversal of 21750265217 is 71256205712.

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 not a de Polignac number, because 21750265217 - 2⁸ = 21750264961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21750265517) 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, 184324223 + ... + 184324340.

It is an arithmetic number, because the mean of its divisors is an integer number (5529728460).

Almost surely, 2^21750265217 is an apocalyptic number.

It is an amenable number.

21750265217 is a deficient number, since it is larger than the sum of its proper divisors (368648623).

21750265217 is an equidigital number, since it uses as much as digits as its factorization.

21750265217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368648622.

The product of its (nonzero) digits is 58800, while the sum is 38.

The spelling of 21750265217 in words is "twenty-one billion, seven hundred fifty million, two hundred sixty-five thousand, two hundred seventeen".