25533638551 has 2 divisors, whose sum is σ = 25533638552. Its totient is φ = 25533638550.

The previous prime is 25533638479. The next prime is 25533638567. The reversal of 25533638551 is 15583633552.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25533638551 - 2³¹ = 23386154903 is a prime.

It is a super-2 number, since 2×25533638551² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25533438551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12766819275 + 12766819276.

It is an arithmetic number, because the mean of its divisors is an integer number (12766819276).

Almost surely, 2^25533638551 is an apocalyptic number.

25533638551 is a deficient number, since it is larger than the sum of its proper divisors (1).

25533638551 is an equidigital number, since it uses as much as digits as its factorization.

25533638551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620000, while the sum is 46.

The spelling of 25533638551 in words is "twenty-five billion, five hundred thirty-three million, six hundred thirty-eight thousand, five hundred fifty-one".