20965894795609 has 9 divisors (see below), whose sum is σ = 21034954728949. Its totient is φ = 20897060898460.

The previous prime is 20965894795591. The next prime is 20965894795627. The reversal of 20965894795609 is 90659749856902.

The square root of 20965894795609 is 4578853.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (20965894795591) and next prime (20965894795627).

It is a de Polignac number, because none of the positive numbers 2^k-20965894795609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20965894795639) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1424015922 + ... + 1424030644.

Almost surely, 2^{20965894795609} is an apocalyptic number.

20965894795609 is the 4578853-rd square number.

20965894795609 is the 2289427-th centered octagonal number.

It is an amenable number.

20965894795609 is a deficient number, since it is larger than the sum of its proper divisors (69059933340).

20965894795609 is an frugal number, since it uses more digits than its factorization.

20965894795609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30068 (or 15034 counting only the distinct ones).

The product of its (nonzero) digits is 2645395200, while the sum is 79.

The spelling of 20965894795609 in words is "twenty trillion, nine hundred sixty-five billion, eight hundred ninety-four million, seven hundred ninety-five thousand, six hundred nine".