25499899409 has 2 divisors, whose sum is σ = 25499899410. Its totient is φ = 25499899408.

The previous prime is 25499899393. The next prime is 25499899459. The reversal of 25499899409 is 90499899452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16692640000 + 8807259409 = 129200^2 + 93847^2 .

It is a cyclic number.

It is not a de Polignac number, because 25499899409 - 2⁴ = 25499899393 is a prime.

It is not a weakly prime, because it can be changed into another prime (25499899459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12749949704 + 12749949705.

It is an arithmetic number, because the mean of its divisors is an integer number (12749949705).

Almost surely, 2^25499899409 is an apocalyptic number.

It is an amenable number.

25499899409 is a deficient number, since it is larger than the sum of its proper divisors (1).

25499899409 is an equidigital number, since it uses as much as digits as its factorization.

25499899409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75582720, while the sum is 68.

The spelling of 25499899409 in words is "twenty-five billion, four hundred ninety-nine million, eight hundred ninety-nine thousand, four hundred nine".