25221620 has 12 divisors (see below), whose sum is σ = 52965444. Its totient is φ = 10088640.

The previous prime is 25221617. The next prime is 25221653. The reversal of 25221620 is 2612252.

It can be written as a sum of positive squares in 2 ways, for example, as 17757796 + 7463824 = 4214^2 + 2732^2 .

It is a super-2 number, since 2×25221620² = 1272260230848800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1261081 = 25221620 / (2 + 5 + 2 + 2 + 1 + 6 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 25221592 and 25221601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 630521 + ... + 630560.

It is an arithmetic number, because the mean of its divisors is an integer number (4413787).

Almost surely, 2^25221620 is an apocalyptic number.

25221620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25221620 is an abundant number, since it is smaller than the sum of its proper divisors (27743824).

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

25221620 is a wasteful number, since it uses less digits than its factorization.

25221620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1261090 (or 1261088 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 25221620 is about 5022.1131010761. The cubic root of 25221620 is about 293.2632609252.

Adding to 25221620 its reverse (2612252), we get a palindrome (27833872).

The spelling of 25221620 in words is "twenty-five million, two hundred twenty-one thousand, six hundred twenty".