20768137357 has 4 divisors (see below), whose sum is σ = 22656149856. Its totient is φ = 18880124860.

The previous prime is 20768137337. The next prime is 20768137381. The reversal of 20768137357 is 75373186702.

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 20768137357 - 2²⁷ = 20633919629 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 20768137357.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20768137307) 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, 944006233 + ... + 944006254.

It is an arithmetic number, because the mean of its divisors is an integer number (5664037464).

Almost surely, 2^20768137357 is an apocalyptic number.

It is an amenable number.

20768137357 is a deficient number, since it is larger than the sum of its proper divisors (1888012499).

20768137357 is a wasteful number, since it uses less digits than its factorization.

20768137357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888012498.

The product of its (nonzero) digits is 1481760, while the sum is 49.

The spelling of 20768137357 in words is "twenty billion, seven hundred sixty-eight million, one hundred thirty-seven thousand, three hundred fifty-seven".