20649082697 has 4 divisors (see below), whose sum is σ = 20649376020. Its totient is φ = 20648789376.

The previous prime is 20649082679. The next prime is 20649082703. The reversal of 20649082697 is 79628094602.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2933738896 + 17715343801 = 54164^2 + 133099^2 .

It is a cyclic number.

It is not a de Polignac number, because 20649082697 - 2³⁴ = 3469213513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20649081697) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29333 + ... + 205325.

It is an arithmetic number, because the mean of its divisors is an integer number (5162344005).

It is a Poulet number, since it divides 2^20649082696-1.

Almost surely, 2^20649082697 is an apocalyptic number.

20649082697 is the 117329-th pentagonal number.

It is an amenable number.

20649082697 is a deficient number, since it is larger than the sum of its proper divisors (293323).

20649082697 is a wasteful number, since it uses less digits than its factorization.

20649082697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293322.

The product of its (nonzero) digits is 2612736, while the sum is 53.

The spelling of 20649082697 in words is "twenty billion, six hundred forty-nine million, eighty-two thousand, six hundred ninety-seven".