25512021 has 12 divisors (see below), whose sum is σ = 36947820. Its totient is φ = 16963200.

The previous prime is 25512017. The next prime is 25512077. The reversal of 25512021 is 12021552.

It can be written as a sum of positive squares in 2 ways, for example, as 19236996 + 6275025 = 4386^2 + 2505^2 .

It is not a de Polignac number, because 25512021 - 2² = 25512017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25511985 and 25512003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25512521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 75 + ... + 7143.

It is an arithmetic number, because the mean of its divisors is an integer number (3078985).

Almost surely, 2^25512021 is an apocalyptic number.

It is an amenable number.

25512021 is a deficient number, since it is larger than the sum of its proper divisors (11435799).

25512021 is a wasteful number, since it uses less digits than its factorization.

25512021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7476 (or 7473 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 25512021 is about 5050.9425853003. The cubic root of 25512021 is about 294.3845100853.

Adding to 25512021 its reverse (12021552), we get a palindrome (37533573).

The spelling of 25512021 in words is "twenty-five million, five hundred twelve thousand, twenty-one".