25221232418 has 6 divisors (see below), whose sum is σ = 37832185521. Its totient is φ = 12610503912.

The previous prime is 25221232417. The next prime is 25221232441. The reversal of 25221232418 is 81423212252.

It can be written as a sum of positive squares in 2 ways, for example, as 25047177169 + 174055249 = 158263^2 + 13193^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=112297.

It is a super-2 number, since 2×25221232418² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25221232417) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 168446 + ... + 280742.

Almost surely, 2^25221232418 is an apocalyptic number.

25221232418 is a deficient number, since it is larger than the sum of its proper divisors (12610953103).

25221232418 is an frugal number, since it uses more digits than its factorization.

25221232418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224596 (or 112299 counting only the distinct ones).

The product of its digits is 15360, while the sum is 32.

Multiplying 25221232418 by its sum of digits (32), we get a square (807079437376 = 898376²).

The spelling of 25221232418 in words is "twenty-five billion, two hundred twenty-one million, two hundred thirty-two thousand, four hundred eighteen".