20761634645 has 8 divisors (see below), whose sum is σ = 24915161304. Its totient is φ = 16608507904.

The previous prime is 20761634633. The next prime is 20761634651. The reversal of 20761634645 is 54643616702.

It can be written as a sum of positive squares in 4 ways, for example, as 4605316 + 20757029329 = 2146^2 + 144073^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20761634645 - 2⁸ = 20761634389 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20761634596 and 20761634605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29477 + ... + 205893.

It is an arithmetic number, because the mean of its divisors is an integer number (3114395163).

Almost surely, 2^20761634645 is an apocalyptic number.

It is an amenable number.

20761634645 is a deficient number, since it is larger than the sum of its proper divisors (4153526659).

20761634645 is a wasteful number, since it uses less digits than its factorization.

20761634645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199959.

The product of its (nonzero) digits is 725760, while the sum is 44.

The spelling of 20761634645 in words is "twenty billion, seven hundred sixty-one million, six hundred thirty-four thousand, six hundred forty-five".