21251862025 has 6 divisors (see below), whose sum is σ = 26352308942. Its totient is φ = 17001489600.

The previous prime is 21251861957. The next prime is 21251862029. The reversal of 21251862025 is 52026815212.

It can be written as a sum of positive squares in 3 ways, for example, as 294088201 + 20957773824 = 17149^2 + 144768^2 .

It is not a de Polignac number, because 21251862025 - 2³³ = 12661927433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21251862029) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 425037216 + ... + 425037265.

Almost surely, 2^21251862025 is an apocalyptic number.

21251862025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21251862025 is a deficient number, since it is larger than the sum of its proper divisors (5100446917).

21251862025 is an equidigital number, since it uses as much as digits as its factorization.

21251862025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850074491 (or 850074486 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 34.

The spelling of 21251862025 in words is "twenty-one billion, two hundred fifty-one million, eight hundred sixty-two thousand, twenty-five".