12635788309 has 4 divisors (see below), whose sum is σ = 12638650860. Its totient is φ = 12632925760.

The previous prime is 12635788241. The next prime is 12635788313. The reversal of 12635788309 is 90388753621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90388753621 = 1493 ⋅60541697.

It can be written as a sum of positive squares in 2 ways, for example, as 5427268900 + 7208519409 = 73670^2 + 84903^2 .

It is a cyclic number.

It is not a de Polignac number, because 12635788309 - 2¹³ = 12635780117 is a prime.

It is a super-2 number, since 2×12635788309² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12635768309) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1424644 + ... + 1433485.

It is an arithmetic number, because the mean of its divisors is an integer number (3159662715).

Almost surely, 2^12635788309 is an apocalyptic number.

It is an amenable number.

12635788309 is a deficient number, since it is larger than the sum of its proper divisors (2862551).

12635788309 is an equidigital number, since it uses as much as digits as its factorization.

12635788309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2862550.

The product of its (nonzero) digits is 2177280, while the sum is 52.

The spelling of 12635788309 in words is "twelve billion, six hundred thirty-five million, seven hundred eighty-eight thousand, three hundred nine".