20318731893 has 6 divisors (see below), whose sum is σ = 29349279414. Its totient is φ = 13545821256.

The previous prime is 20318731877. The next prime is 20318731903. The reversal of 20318731893 is 39813781302.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 16068604644 + 4250127249 = 126762^2 + 65193^2 .

It is not a de Polignac number, because 20318731893 - 2⁴ = 20318731877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20318731843) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1128818430 + ... + 1128818447.

It is an arithmetic number, because the mean of its divisors is an integer number (4891546569).

Almost surely, 2^20318731893 is an apocalyptic number.

It is an amenable number.

20318731893 is a deficient number, since it is larger than the sum of its proper divisors (9030547521).

20318731893 is a wasteful number, since it uses less digits than its factorization.

20318731893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2257636883 (or 2257636880 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 20318731893 in words is "twenty billion, three hundred eighteen million, seven hundred thirty-one thousand, eight hundred ninety-three".