25599999949 has 2 divisors, whose sum is σ = 25599999950. Its totient is φ = 25599999948.

The previous prime is 25599999937. The next prime is 25599999959. The reversal of 25599999949 is 94999999552.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24620748100 + 979251849 = 156910^2 + 31293^2 .

It is a cyclic number.

It is not a de Polignac number, because 25599999949 - 2¹⁹ = 25599475661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25599999959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12799999974 + 12799999975.

It is an arithmetic number, because the mean of its divisors is an integer number (12799999975).

Almost surely, 2^25599999949 is an apocalyptic number.

It is an amenable number.

25599999949 is a deficient number, since it is larger than the sum of its proper divisors (1).

25599999949 is an equidigital number, since it uses as much as digits as its factorization.

25599999949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 956593800, while the sum is 79.

The spelling of 25599999949 in words is "twenty-five billion, five hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred forty-nine".