25401861 has 6 divisors (see below), whose sum is σ = 36691590. Its totient is φ = 16934568.

The previous prime is 25401839. The next prime is 25401881. The reversal of 25401861 is 16810452.

It can be written as a sum of positive squares in only one way, i.e., 22268961 + 3132900 = 4719^2 + 1770^2 .

It is not a de Polignac number, because 25401861 - 2⁵ = 25401829 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25401811) 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, 1411206 + ... + 1411223.

It is an arithmetic number, because the mean of its divisors is an integer number (6115265).

Almost surely, 2^25401861 is an apocalyptic number.

It is an amenable number.

25401861 is a deficient number, since it is larger than the sum of its proper divisors (11289729).

25401861 is a wasteful number, since it uses less digits than its factorization.

25401861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2822435 (or 2822432 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 25401861 is about 5040.0258927906. The cubic root of 25401861 is about 293.9601848068.

It can be divided in two parts, 25401 and 861, that added together give a palindrome (26262).

The spelling of 25401861 in words is "twenty-five million, four hundred one thousand, eight hundred sixty-one".