20657440269 has 6 divisors (see below), whose sum is σ = 29838524846. Its totient is φ = 13771626840.

The previous prime is 20657440267. The next prime is 20657440339. The reversal of 20657440269 is 96204475602.

It can be written as a sum of positive squares in only one way, i.e., 17486624169 + 3170816100 = 132237^2 + 56310^2 .

It is not a de Polignac number, because 20657440269 - 2¹ = 20657440267 is a prime.

It is a super-2 number, since 2×20657440269² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20657440261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1147635562 + ... + 1147635579.

Almost surely, 2^20657440269 is an apocalyptic number.

It is an amenable number.

20657440269 is a deficient number, since it is larger than the sum of its proper divisors (9181084577).

20657440269 is a wasteful number, since it uses less digits than its factorization.

20657440269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2295271147 (or 2295271144 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The spelling of 20657440269 in words is "twenty billion, six hundred fifty-seven million, four hundred forty thousand, two hundred sixty-nine".