25215231220645 has 4 divisors (see below), whose sum is σ = 30258277464780. Its totient is φ = 20172184976512.

The previous prime is 25215231220633. The next prime is 25215231220667. The reversal of 25215231220645 is 54602213251252.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15863763248356 + 9351467972289 = 3982934^2 + 3058017^2 .

It is a cyclic number.

It is not a de Polignac number, because 25215231220645 - 2³³ = 25206641286053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25215231220598 and 25215231220607.

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, 2521523122060 + ... + 2521523122069.

It is an arithmetic number, because the mean of its divisors is an integer number (7564569366195).

Almost surely, 2^{25215231220645} is an apocalyptic number.

It is an amenable number.

25215231220645 is a deficient number, since it is larger than the sum of its proper divisors (5043046244135).

25215231220645 is an equidigital number, since it uses as much as digits as its factorization.

25215231220645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5043046244134.

The product of its (nonzero) digits is 288000, while the sum is 40.

Adding to 25215231220645 its reverse (54602213251252), we get a palindrome (79817444471897).

The spelling of 25215231220645 in words is "twenty-five trillion, two hundred fifteen billion, two hundred thirty-one million, two hundred twenty thousand, six hundred forty-five".