20379789581 has 2 divisors, whose sum is σ = 20379789582. Its totient is φ = 20379789580.

The previous prime is 20379789503. The next prime is 20379789583. The reversal of 20379789581 is 18598797302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10590468100 + 9789321481 = 102910^2 + 98941^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20379789581 is a prime.

It is a super-2 number, since 2×20379789581² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 20379789583, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20379789581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20379789583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10189894790 + 10189894791.

It is an arithmetic number, because the mean of its divisors is an integer number (10189894791).

Almost surely, 2^20379789581 is an apocalyptic number.

It is an amenable number.

20379789581 is a deficient number, since it is larger than the sum of its proper divisors (1).

20379789581 is an equidigital number, since it uses as much as digits as its factorization.

20379789581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7620480, while the sum is 59.

The spelling of 20379789581 in words is "twenty billion, three hundred seventy-nine million, seven hundred eighty-nine thousand, five hundred eighty-one".