21225774257 has 4 divisors (see below), whose sum is σ = 21524728896. Its totient is φ = 20926819620.

The previous prime is 21225774233. The next prime is 21225774277. The reversal of 21225774257 is 75247752212.

It is a happy number.

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 21225774257 - 2⁸ = 21225774001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21225774217) 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, 149477213 + ... + 149477354.

It is an arithmetic number, because the mean of its divisors is an integer number (5381182224).

Almost surely, 2^21225774257 is an apocalyptic number.

It is an amenable number.

21225774257 is a deficient number, since it is larger than the sum of its proper divisors (298954639).

21225774257 is an equidigital number, since it uses as much as digits as its factorization.

21225774257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298954638.

The product of its digits is 548800, while the sum is 44.

The spelling of 21225774257 in words is "twenty-one billion, two hundred twenty-five million, seven hundred seventy-four thousand, two hundred fifty-seven".