20764356749 has 2 divisors, whose sum is σ = 20764356750. Its totient is φ = 20764356748.

The previous prime is 20764356709. The next prime is 20764356757. The reversal of 20764356749 is 94765346702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20587945225 + 176411524 = 143485^2 + 13282^2 .

It is a cyclic number.

It is not a de Polignac number, because 20764356749 - 2¹⁶ = 20764291213 is a prime.

It is a super-2 number, since 2×20764356749² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20764356749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20764356709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10382178374 + 10382178375.

It is an arithmetic number, because the mean of its divisors is an integer number (10382178375).

Almost surely, 2^20764356749 is an apocalyptic number.

It is an amenable number.

20764356749 is a deficient number, since it is larger than the sum of its proper divisors (1).

20764356749 is an equidigital number, since it uses as much as digits as its factorization.

20764356749 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 53.

The spelling of 20764356749 in words is "twenty billion, seven hundred sixty-four million, three hundred fifty-six thousand, seven hundred forty-nine".