20645165313 has 48 divisors (see below), whose sum is σ = 32698884816. Its totient is φ = 12500766720.

The previous prime is 20645165257. The next prime is 20645165341. The reversal of 20645165313 is 31356154602.

20645165313 is a `hidden beast` number, since 2 + 0 + 645 + 1 + 6 + 5 + 3 + 1 + 3 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 1790305344 + 18854859969 = 42312^2 + 137313^2 .

It is not a de Polignac number, because 20645165313 - 2⁶ = 20645165249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20645115313) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 473781 + ... + 515517.

It is an arithmetic number, because the mean of its divisors is an integer number (681226767).

Almost surely, 2^20645165313 is an apocalyptic number.

It is an amenable number.

20645165313 is a deficient number, since it is larger than the sum of its proper divisors (12053719503).

20645165313 is a wasteful number, since it uses less digits than its factorization.

20645165313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41874 (or 41871 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 20645165313 in words is "twenty billion, six hundred forty-five million, one hundred sixty-five thousand, three hundred thirteen".