20964257989 has 2 divisors, whose sum is σ = 20964257990. Its totient is φ = 20964257988.

The previous prime is 20964257947. The next prime is 20964258023. The reversal of 20964257989 is 98975246902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20690520964 + 273737025 = 143842^2 + 16545^2 .

It is a cyclic number.

It is not a de Polignac number, because 20964257989 - 2¹¹ = 20964255941 is a prime.

It is a super-2 number, since 2×20964257989² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20964257929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10482128994 + 10482128995.

It is an arithmetic number, because the mean of its divisors is an integer number (10482128995).

Almost surely, 2^20964257989 is an apocalyptic number.

It is an amenable number.

20964257989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20964257989 is an equidigital number, since it uses as much as digits as its factorization.

20964257989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19595520, while the sum is 61.

The spelling of 20964257989 in words is "twenty billion, nine hundred sixty-four million, two hundred fifty-seven thousand, nine hundred eighty-nine".