20723657489 has 16 divisors (see below), whose sum is σ = 21361120704. Its totient is φ = 20093572800.

The previous prime is 20723657477. The next prime is 20723657519. The reversal of 20723657489 is 98475632702.

It is a cyclic number.

It is not a de Polignac number, because 20723657489 - 2⁸ = 20723657233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20723657489.

It is not an unprimeable number, because it can be changed into a prime (20723657459) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9678359 + ... + 9680499.

It is an arithmetic number, because the mean of its divisors is an integer number (1335070044).

Almost surely, 2^20723657489 is an apocalyptic number.

It is an amenable number.

20723657489 is a deficient number, since it is larger than the sum of its proper divisors (637463215).

20723657489 is a wasteful number, since it uses less digits than its factorization.

20723657489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3728.

The product of its (nonzero) digits is 5080320, while the sum is 53.

The spelling of 20723657489 in words is "twenty billion, seven hundred twenty-three million, six hundred fifty-seven thousand, four hundred eighty-nine".