20993611579 has 2 divisors, whose sum is σ = 20993611580. Its totient is φ = 20993611578.

The previous prime is 20993611519. The next prime is 20993611591. The reversal of 20993611579 is 97511639902.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20993611579 - 2¹¹ = 20993609531 is a prime.

It is not a weakly prime, because it can be changed into another prime (20993611519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10496805789 + 10496805790.

It is an arithmetic number, because the mean of its divisors is an integer number (10496805790).

Almost surely, 2^20993611579 is an apocalyptic number.

20993611579 is a deficient number, since it is larger than the sum of its proper divisors (1).

20993611579 is an equidigital number, since it uses as much as digits as its factorization.

20993611579 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 918540, while the sum is 52.

The spelling of 20993611579 in words is "twenty billion, nine hundred ninety-three million, six hundred eleven thousand, five hundred seventy-nine".