25531020 has 144 divisors (see below), whose sum is σ = 82424160. Its totient is φ = 6386688.

The previous prime is 25531019. The next prime is 25531021. The reversal of 25531020 is 2013552.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (25531019) and next prime (25531021).

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 = 25530984 and 25531002.

It is not an unprimeable number, because it can be changed into a prime (25531021) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 349704 + ... + 349776.

It is an arithmetic number, because the mean of its divisors is an integer number (572390).

Almost surely, 2^25531020 is an apocalyptic number.

25531020 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 25531020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41212080).

25531020 is an abundant number, since it is smaller than the sum of its proper divisors (56893140).

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

25531020 is a wasteful number, since it uses less digits than its factorization.

25531020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184 (or 179 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 25531020 is about 5052.8229733487. The cubic root of 25531020 is about 294.4575687622.

Adding to 25531020 its reverse (2013552), we get a palindrome (27544572).

The spelling of 25531020 in words is "twenty-five million, five hundred thirty-one thousand, twenty".