21001253025 has 96 divisors (see below), whose sum is σ = 38054707200. Its totient is φ = 10173772800.

The previous prime is 21001253023. The next prime is 21001253027. The reversal of 21001253025 is 52035210012.

It is an interprime number because it is at equal distance from previous prime (21001253023) and next prime (21001253027).

It is not a de Polignac number, because 21001253025 - 2¹ = 21001253023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21001252992 and 21001253010.

It is not an unprimeable number, because it can be changed into a prime (21001253023) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 28418106 + ... + 28418844.

It is an arithmetic number, because the mean of its divisors is an integer number (396403200).

Almost surely, 2^21001253025 is an apocalyptic number.

21001253025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21001253025 is a deficient number, since it is larger than the sum of its proper divisors (17053454175).

21001253025 is a wasteful number, since it uses less digits than its factorization.

21001253025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1519 (or 1514 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

Adding to 21001253025 its reverse (52035210012), we get a palindrome (73036463037).

The spelling of 21001253025 in words is "twenty-one billion, one million, two hundred fifty-three thousand, twenty-five".