25491540 has 96 divisors (see below), whose sum is σ = 76608000. Its totient is φ = 6314112.

The previous prime is 25491539. The next prime is 25491553. The reversal of 25491540 is 4519452.

It is a super-2 number, since 2×25491540² = 1299637223143200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 25491498 and 25491507.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 67071 + ... + 67449.

It is an arithmetic number, because the mean of its divisors is an integer number (798000).

Almost surely, 2^25491540 is an apocalyptic number.

25491540 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 25491540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38304000).

25491540 is an abundant number, since it is smaller than the sum of its proper divisors (51116460).

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

25491540 is a wasteful number, since it uses less digits than its factorization.

25491540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469 (or 467 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 25491540 is about 5048.9147348712. The cubic root of 25491540 is about 294.3057118944.

The spelling of 25491540 in words is "twenty-five million, four hundred ninety-one thousand, five hundred forty".