25551015551 has 4 divisors (see below), whose sum is σ = 25558284072. Its totient is φ = 25543747032.

The previous prime is 25551015499. The next prime is 25551015557. The reversal of 25551015551 is 15551015552.

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 25551015551 - 2¹⁰ = 25551014527 is a prime.

It is a super-3 number, since 3×25551015551³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25551015557) 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, 3628985 + ... + 3636018.

It is an arithmetic number, because the mean of its divisors is an integer number (6389571018).

Almost surely, 2^25551015551 is an apocalyptic number.

25551015551 is a deficient number, since it is larger than the sum of its proper divisors (7268521).

25551015551 is an equidigital number, since it uses as much as digits as its factorization.

25551015551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7268520.

The product of its (nonzero) digits is 31250, while the sum is 35.

Subtracting from 25551015551 its reverse (15551015552), we obtain a palindrome (9999999999).

It can be divided in two parts, 2555101 and 5551, that added together give a palindrome (2560652).

The spelling of 25551015551 in words is "twenty-five billion, five hundred fifty-one million, fifteen thousand, five hundred fifty-one".