25215443915 has 4 divisors (see below), whose sum is σ = 30258532704. Its totient is φ = 20172355128.

The previous prime is 25215443863. The next prime is 25215443917. The reversal of 25215443915 is 51934451252.

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

It is a cyclic number.

It is not a de Polignac number, because 25215443915 - 2¹² = 25215439819 is a prime.

It is a super-2 number, since 2×25215443915² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25215443917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2521544387 + ... + 2521544396.

It is an arithmetic number, because the mean of its divisors is an integer number (7564633176).

Almost surely, 2^25215443915 is an apocalyptic number.

25215443915 is a deficient number, since it is larger than the sum of its proper divisors (5043088789).

25215443915 is an equidigital number, since it uses as much as digits as its factorization.

25215443915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5043088788.

The product of its digits is 216000, while the sum is 41.

The spelling of 25215443915 in words is "twenty-five billion, two hundred fifteen million, four hundred forty-three thousand, nine hundred fifteen".