20965723481 has 4 divisors (see below), whose sum is σ = 21411802752. Its totient is φ = 20519644212.

The previous prime is 20965723459. The next prime is 20965723523. The reversal of 20965723481 is 18432756902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20965723481 - 2²⁶ = 20898614617 is a prime.

It is a super-2 number, since 2×20965723481² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 446079223 = 20965723481 / (2 + 0 + 9 + 6 + 5 + 7 + 2 + 3 + 4 + 8 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20965723381) 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, 223039565 + ... + 223039658.

It is an arithmetic number, because the mean of its divisors is an integer number (5352950688).

It is a 1-persistent number, because it is pandigital, but 2⋅20965723481 = 41931446962 is not.

Almost surely, 2^20965723481 is an apocalyptic number.

It is an amenable number.

20965723481 is a deficient number, since it is larger than the sum of its proper divisors (446079271).

20965723481 is an equidigital number, since it uses as much as digits as its factorization.

20965723481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446079270.

The product of its (nonzero) digits is 725760, while the sum is 47.

The spelling of 20965723481 in words is "twenty billion, nine hundred sixty-five million, seven hundred twenty-three thousand, four hundred eighty-one".