21952867225 has 9 divisors (see below), whose sum is σ = 27222474013. Its totient is φ = 17561701120.

The previous prime is 21952867213. The next prime is 21952867249. The reversal of 21952867225 is 52276825912.

The square root of 21952867225 is 148165.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 6236734729 + 15716132496 = 78973^2 + 125364^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21952867225 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 726009 + ... + 755641.

Almost surely, 2^21952867225 is an apocalyptic number.

21952867225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21952867225 is the 148165-th square number.

21952867225 is the 74083-rd centered octagonal number.

It is an amenable number.

21952867225 is a deficient number, since it is larger than the sum of its proper divisors (5269606788).

21952867225 is an frugal number, since it uses more digits than its factorization.

21952867225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59276 (or 29638 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 49.

Multiplying 21952867225 by its sum of digits (49), we get a square (1075690494025 = 1037155²).

The spelling of 21952867225 in words is "twenty-one billion, nine hundred fifty-two million, eight hundred sixty-seven thousand, two hundred twenty-five".