20950010581 has 4 divisors (see below), whose sum is σ = 20952277164. Its totient is φ = 20947744000.

The previous prime is 20950010563. The next prime is 20950010593. The reversal of 20950010581 is 18501005902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11237908081 + 9712102500 = 106009^2 + 98550^2 .

It is a cyclic number.

It is not a de Polignac number, because 20950010581 - 2¹¹ = 20950008533 is a prime.

It is a super-2 number, since 2×20950010581² (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 (20950010561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1119370 + ... + 1137931.

It is an arithmetic number, because the mean of its divisors is an integer number (5238069291).

Almost surely, 2^20950010581 is an apocalyptic number.

It is an amenable number.

20950010581 is a deficient number, since it is larger than the sum of its proper divisors (2266583).

20950010581 is an equidigital number, since it uses as much as digits as its factorization.

20950010581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2266582.

The product of its (nonzero) digits is 3600, while the sum is 31.

The spelling of 20950010581 in words is "twenty billion, nine hundred fifty million, ten thousand, five hundred eighty-one".