25221906 has 12 divisors (see below), whose sum is σ = 54647502. Its totient is φ = 8407296.

The previous prime is 25221899. The next prime is 25221913. The reversal of 25221906 is 60912252.

It is an interprime number because it is at equal distance from previous prime (25221899) and next prime (25221913).

It can be written as a sum of positive squares in only one way, i.e., 21706281 + 3515625 = 4659^2 + 1875^2 .

It is a super-3 number, since 3×25221906³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 25221906.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 700591 + ... + 700626.

Almost surely, 2^25221906 is an apocalyptic number.

25221906 is an abundant number, since it is smaller than the sum of its proper divisors (29425596).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25221906 is a wasteful number, since it uses less digits than its factorization.

25221906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1401225 (or 1401222 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 25221906 is about 5022.1415750654. The cubic root of 25221906 is about 293.2643694051.

The spelling of 25221906 in words is "twenty-five million, two hundred twenty-one thousand, nine hundred six".