25221971 has 2 divisors, whose sum is σ = 25221972. Its totient is φ = 25221970.

The previous prime is 25221953. The next prime is 25221979. The reversal of 25221971 is 17912252.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25221971 - 2¹⁰ = 25220947 is a prime.

It is a super-2 number, since 2×25221971² = 1272295642249682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25221979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12610985 + 12610986.

It is an arithmetic number, because the mean of its divisors is an integer number (12610986).

Almost surely, 2^25221971 is an apocalyptic number.

25221971 is a deficient number, since it is larger than the sum of its proper divisors (1).

25221971 is an equidigital number, since it uses as much as digits as its factorization.

25221971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 29.

The square root of 25221971 is about 5022.1480464040. The cubic root of 25221971 is about 293.2646213312.

The spelling of 25221971 in words is "twenty-five million, two hundred twenty-one thousand, nine hundred seventy-one".