251201021025 has 48 divisors (see below), whose sum is σ = 431109335808. Its totient is φ = 128973696000.

The previous prime is 251201021023. The next prime is 251201021039. The reversal of 251201021025 is 520120102152.

It is not a de Polignac number, because 251201021025 - 2¹ = 251201021023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 251201020992 and 251201021010.

It is not an unprimeable number, because it can be changed into a prime (251201021023) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 369096 + ... + 799145.

It is an arithmetic number, because the mean of its divisors is an integer number (8981444496).

Almost surely, 2^251201021025 is an apocalyptic number.

251201021025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

251201021025 is a deficient number, since it is larger than the sum of its proper divisors (179908314783).

251201021025 is a wasteful number, since it uses less digits than its factorization.

251201021025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1168362 (or 1168357 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 21.

Adding to 251201021025 its reverse (520120102152), we get a palindrome (771321123177).

The spelling of 251201021025 in words is "two hundred fifty-one billion, two hundred one million, twenty-one thousand, twenty-five".