25389981 has 6 divisors (see below), whose sum is σ = 36674430. Its totient is φ = 16926648.

The previous prime is 25389979. The next prime is 25389983. The reversal of 25389981 is 18998352.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (25389979) and next prime (25389983).

It can be written as a sum of positive squares in only one way, i.e., 21622500 + 3767481 = 4650^2 + 1941^2 .

It is not a de Polignac number, because 25389981 - 2¹ = 25389979 is a prime.

It is a super-2 number, since 2×25389981² = 1289302270360722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25389983) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1410546 + ... + 1410563.

It is an arithmetic number, because the mean of its divisors is an integer number (6112405).

Almost surely, 2^25389981 is an apocalyptic number.

It is an amenable number.

25389981 is a deficient number, since it is larger than the sum of its proper divisors (11284449).

25389981 is a wasteful number, since it uses less digits than its factorization.

25389981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2821115 (or 2821112 counting only the distinct ones).

The product of its digits is 155520, while the sum is 45.

The square root of 25389981 is about 5038.8471895861. The cubic root of 25389981 is about 293.9143510054.

The spelling of 25389981 in words is "twenty-five million, three hundred eighty-nine thousand, nine hundred eighty-one".