20761752661 has 8 divisors (see below), whose sum is σ = 22725349304. Its totient is φ = 18850518720.

The previous prime is 20761752659. The next prime is 20761752679. The reversal of 20761752661 is 16625716702.

It can be written as a sum of positive squares in 4 ways, for example, as 857904100 + 19903848561 = 29290^2 + 141081^2 .

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 20761752661 - 2¹ = 20761752659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20761752161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13089846 + ... + 13091431.

It is an arithmetic number, because the mean of its divisors is an integer number (2840668663).

Almost surely, 2^20761752661 is an apocalyptic number.

It is an amenable number.

20761752661 is a deficient number, since it is larger than the sum of its proper divisors (1963596643).

20761752661 is a wasteful number, since it uses less digits than its factorization.

20761752661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26181351.

The product of its (nonzero) digits is 211680, while the sum is 43.

The spelling of 20761752661 in words is "twenty billion, seven hundred sixty-one million, seven hundred fifty-two thousand, six hundred sixty-one".