20423233657 has 4 divisors (see below), whose sum is σ = 20579136336. Its totient is φ = 20267330980.

The previous prime is 20423233553. The next prime is 20423233667. The reversal of 20423233657 is 75633232402.

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 a de Polignac number, because none of the positive numbers 2^k-20423233657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20423233667) 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, 77951143 + ... + 77951404.

It is an arithmetic number, because the mean of its divisors is an integer number (5144784084).

Almost surely, 2^20423233657 is an apocalyptic number.

It is an amenable number.

20423233657 is a deficient number, since it is larger than the sum of its proper divisors (155902679).

20423233657 is a wasteful number, since it uses less digits than its factorization.

20423233657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155902678.

The product of its (nonzero) digits is 181440, while the sum is 37.

The spelling of 20423233657 in words is "twenty billion, four hundred twenty-three million, two hundred thirty-three thousand, six hundred fifty-seven".