25572721 has 4 divisors (see below), whose sum is σ = 25744500. Its totient is φ = 25400944.

The previous prime is 25572719. The next prime is 25572731. The reversal of 25572721 is 12727552.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10080625 + 15492096 = 3175^2 + 3936^2 .

It is a cyclic number.

It is not a de Polignac number, because 25572721 - 2¹ = 25572719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25572731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85666 + ... + 85963.

It is an arithmetic number, because the mean of its divisors is an integer number (6436125).

Almost surely, 2^25572721 is an apocalyptic number.

It is an amenable number.

25572721 is a deficient number, since it is larger than the sum of its proper divisors (171779).

25572721 is a wasteful number, since it uses less digits than its factorization.

25572721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171778.

The product of its digits is 9800, while the sum is 31.

The square root of 25572721 is about 5056.9477948660. The cubic root of 25572721 is about 294.6177986284.

The spelling of 25572721 in words is "twenty-five million, five hundred seventy-two thousand, seven hundred twenty-one".