25123981 has 16 divisors (see below), whose sum is σ = 27353088. Its totient is φ = 23007600.

The previous prime is 25123957. The next prime is 25123993. The reversal of 25123981 is 18932152.

It is a cyclic number.

It is not a de Polignac number, because 25123981 - 2¹⁷ = 24992909 is a prime.

It is a super-2 number, since 2×25123981² = 1262428842576722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

25123981 is a Rhonda number in base 10.

Its product of digits (4320) is a multiple of the sum of its prime divisors (432).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25123951) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118966 + ... + 119176.

It is an arithmetic number, because the mean of its divisors is an integer number (1709568).

Almost surely, 2^25123981 is an apocalyptic number.

It is an amenable number.

25123981 is a deficient number, since it is larger than the sum of its proper divisors (2229107).

25123981 is a wasteful number, since it uses less digits than its factorization.

25123981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432.

The product of its digits is 4320, while the sum is 31.

The square root of 25123981 is about 5012.3827667089. The cubic root of 25123981 is about 292.8843405012.

The spelling of 25123981 in words is "twenty-five million, one hundred twenty-three thousand, nine hundred eighty-one".