21769942993 has 2 divisors, whose sum is σ = 21769942994. Its totient is φ = 21769942992.

The previous prime is 21769942991. The next prime is 21769943029. The reversal of 21769942993 is 39924996712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18592140609 + 3177802384 = 136353^2 + 56372^2 .

It is a cyclic number.

It is not a de Polignac number, because 21769942993 - 2¹ = 21769942991 is a prime.

Together with 21769942991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21769942991) 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 as a sum of consecutive naturals, namely, 10884971496 + 10884971497.

It is an arithmetic number, because the mean of its divisors is an integer number (10884971497).

Almost surely, 2^21769942993 is an apocalyptic number.

It is an amenable number.

21769942993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21769942993 is an equidigital number, since it uses as much as digits as its factorization.

21769942993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13226976, while the sum is 61.

The spelling of 21769942993 in words is "twenty-one billion, seven hundred sixty-nine million, nine hundred forty-two thousand, nine hundred ninety-three".