25209999999 has 24 divisors (see below), whose sum is σ = 36716838912. Its totient is φ = 16667214480.

The previous prime is 25209999977. The next prime is 25210000021. The reversal of 25209999999 is 99999990252.

25209999999 is a `hidden beast` number, since 2 + 520 + 9 + 9 + 9 + 9 + 9 + 99 = 666.

It is an interprime number because it is at equal distance from previous prime (25209999977) and next prime (25210000021).

It is not a de Polignac number, because 25209999999 - 2²¹ = 25207902847 is a prime.

25209999999 is a modest number, since divided by 999999 gives 25209 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25209999929) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5016402 + ... + 5021424.

It is an arithmetic number, because the mean of its divisors is an integer number (1529868288).

Almost surely, 2^25209999999 is an apocalyptic number.

25209999999 is a deficient number, since it is larger than the sum of its proper divisors (11506838913).

25209999999 is a wasteful number, since it uses less digits than its factorization.

25209999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9547 (or 9544 counting only the distinct ones).

The product of its (nonzero) digits is 95659380, while the sum is 72.

The spelling of 25209999999 in words is "twenty-five billion, two hundred nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".