25971021 has 6 divisors (see below), whose sum is σ = 37513710. Its totient is φ = 17314008.

The previous prime is 25970983. The next prime is 25971031. The reversal of 25971021 is 12017952.

It can be written as a sum of positive squares in only one way, i.e., 19236996 + 6734025 = 4386^2 + 2595^2 .

It is not a de Polignac number, because 25971021 - 2⁶ = 25970957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25971031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1442826 + ... + 1442843.

It is an arithmetic number, because the mean of its divisors is an integer number (6252285).

Almost surely, 2^25971021 is an apocalyptic number.

It is an amenable number.

25971021 is a deficient number, since it is larger than the sum of its proper divisors (11542689).

25971021 is a wasteful number, since it uses less digits than its factorization.

25971021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2885675 (or 2885672 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 25971021 is about 5096.1770966088. The cubic root of 25971021 is about 296.1395015986.

Adding to 25971021 its reverse (12017952), we get a palindrome (37988973).

The spelling of 25971021 in words is "twenty-five million, nine hundred seventy-one thousand, twenty-one".