21989741764797 has 6 divisors (see below), whose sum is σ = 31762960326942. Its totient is φ = 14659827843192.

The previous prime is 21989741764759. The next prime is 21989741764799. The reversal of 21989741764797 is 79746714798912.

21989741764797 is a `hidden beast` number, since 2 + 1 + 9 + 8 + 9 + 74 + 1 + 76 + 479 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20429188657956 + 1560553106841 = 4519866^2 + 1249221^2 .

It is not a de Polignac number, because 21989741764797 - 2¹⁴ = 21989741748413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21989741764799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1221652320258 + ... + 1221652320275.

It is an arithmetic number, because the mean of its divisors is an integer number (5293826721157).

Almost surely, 2^{21989741764797} is an apocalyptic number.

It is an amenable number.

21989741764797 is a deficient number, since it is larger than the sum of its proper divisors (9773218562145).

21989741764797 is a wasteful number, since it uses less digits than its factorization.

21989741764797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2443304640539 (or 2443304640536 counting only the distinct ones).

The product of its digits is 2688505344, while the sum is 81.

The spelling of 21989741764797 in words is "twenty-one trillion, nine hundred eighty-nine billion, seven hundred forty-one million, seven hundred sixty-four thousand, seven hundred ninety-seven".