21567747225 has 24 divisors (see below), whose sum is σ = 36190902880. Its totient is φ = 11331112320.

The previous prime is 21567747181. The next prime is 21567747239. The reversal of 21567747225 is 52274776512.

It is a happy number.

It is not a de Polignac number, because 21567747225 - 2¹⁴ = 21567730841 is a prime.

It is a super-2 number, since 2×21567747225² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2141020 + ... + 2151069.

Almost surely, 2^21567747225 is an apocalyptic number.

21567747225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21567747225 is a deficient number, since it is larger than the sum of its proper divisors (14623155655).

21567747225 is a wasteful number, since it uses less digits than its factorization.

21567747225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4292169 (or 4292164 counting only the distinct ones).

The product of its digits is 1646400, while the sum is 48.

The spelling of 21567747225 in words is "twenty-one billion, five hundred sixty-seven million, seven hundred forty-seven thousand, two hundred twenty-five".