20969726391 has 20 divisors (see below), whose sum is σ = 31329589104. Its totient is φ = 13977835200.

The previous prime is 20969726383. The next prime is 20969726411. The reversal of 20969726391 is 19362796902.

20969726391 is a `hidden beast` number, since 209 + 6 + 97 + 263 + 91 = 666.

It is not a de Polignac number, because 20969726391 - 2³ = 20969726383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20969726341) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 757606 + ... + 784796.

Almost surely, 2^20969726391 is an apocalyptic number.

20969726391 is a deficient number, since it is larger than the sum of its proper divisors (10359862713).

20969726391 is an equidigital number, since it uses as much as digits as its factorization.

20969726391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36724 (or 36715 counting only the distinct ones).

The product of its (nonzero) digits is 2204496, while the sum is 54.

The spelling of 20969726391 in words is "twenty billion, nine hundred sixty-nine million, seven hundred twenty-six thousand, three hundred ninety-one".