20556266737 has 8 divisors (see below), whose sum is σ = 21772384200. Its totient is φ = 19340918784.

The previous prime is 20556266713. The next prime is 20556266761. The reversal of 20556266737 is 73766265502.

It is an interprime number because it is at equal distance from previous prime (20556266713) and next prime (20556266761).

It can be written as a sum of positive squares in 4 ways, for example, as 3863368336 + 16692898401 = 62156^2 + 129201^2 .

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 20556266737 - 2¹¹ = 20556264689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20556260737) 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, 136912 + ... + 244657.

It is an arithmetic number, because the mean of its divisors is an integer number (2721548025).

Almost surely, 2^20556266737 is an apocalyptic number.

It is an amenable number.

20556266737 is a deficient number, since it is larger than the sum of its proper divisors (1216117463).

20556266737 is a wasteful number, since it uses less digits than its factorization.

20556266737 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384755.

The product of its (nonzero) digits is 3175200, while the sum is 49.

The spelling of 20556266737 in words is "twenty billion, five hundred fifty-six million, two hundred sixty-six thousand, seven hundred thirty-seven".