25545540 has 72 divisors (see below), whose sum is σ = 73749312. Its totient is φ = 6606720.

The previous prime is 25545539. The next prime is 25545563. The reversal of 25545540 is 4554552.

It is a super-2 number, since 2×25545540² = 1305149227783200, 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 = 25545498 and 25545507.

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 23 ways as a sum of consecutive naturals, for example, 81985 + ... + 82295.

It is an arithmetic number, because the mean of its divisors is an integer number (1024296).

Almost surely, 2^25545540 is an apocalyptic number.

25545540 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 25545540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36874656).

25545540 is an abundant number, since it is smaller than the sum of its proper divisors (48203772).

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

25545540 is a wasteful number, since it uses less digits than its factorization.

25545540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397 (or 358 counting only the distinct ones).

The product of its (nonzero) digits is 20000, while the sum is 30.

The square root of 25545540 is about 5054.2595896926. The cubic root of 25545540 is about 294.5133794796.

The spelling of 25545540 in words is "twenty-five million, five hundred forty-five thousand, five hundred forty".