25621020 has 72 divisors (see below), whose sum is σ = 79838304. Its totient is φ = 6645888.

The previous prime is 25621019. The next prime is 25621033. The reversal of 25621020 is 2012652.

25621020 is a `hidden beast` number, since 2 + 562 + 102 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 25620984 and 25621002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4737 + ... + 8583.

Almost surely, 2^25621020 is an apocalyptic number.

25621020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25621020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39919152).

25621020 is an abundant number, since it is smaller than the sum of its proper divisors (54217284).

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

25621020 is a wasteful number, since it uses less digits than its factorization.

25621020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3899 (or 3894 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 25621020 is about 5061.7210511841. The cubic root of 25621020 is about 294.8031627632.

Adding to 25621020 its reverse (2012652), we get a palindrome (27633672).

The spelling of 25621020 in words is "twenty-five million, six hundred twenty-one thousand, twenty".