25385551693 has 2 divisors, whose sum is σ = 25385551694. Its totient is φ = 25385551692.

The previous prime is 25385551691. The next prime is 25385551717. The reversal of 25385551693 is 39615558352.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23226369604 + 2159182089 = 152402^2 + 46467^2 .

It is a cyclic number.

It is not a de Polignac number, because 25385551693 - 2¹ = 25385551691 is a prime.

Together with 25385551691, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 25385551693.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25385551691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12692775846 + 12692775847.

It is an arithmetic number, because the mean of its divisors is an integer number (12692775847).

Almost surely, 2^25385551693 is an apocalyptic number.

It is an amenable number.

25385551693 is a deficient number, since it is larger than the sum of its proper divisors (1).

25385551693 is an equidigital number, since it uses as much as digits as its factorization.

25385551693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4860000, while the sum is 52.

The spelling of 25385551693 in words is "twenty-five billion, three hundred eighty-five million, five hundred fifty-one thousand, six hundred ninety-three".