20447231993 has 4 divisors (see below), whose sum is σ = 20735221248. Its totient is φ = 20159242740.

The previous prime is 20447231977. The next prime is 20447232011. The reversal of 20447231993 is 39913274402.

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 20447231993 - 2⁴ = 20447231977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20447231963) 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, 143994521 + ... + 143994662.

It is an arithmetic number, because the mean of its divisors is an integer number (5183805312).

Almost surely, 2^20447231993 is an apocalyptic number.

It is an amenable number.

20447231993 is a deficient number, since it is larger than the sum of its proper divisors (287989255).

20447231993 is an equidigital number, since it uses as much as digits as its factorization.

20447231993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287989254.

The product of its (nonzero) digits is 326592, while the sum is 44.

The spelling of 20447231993 in words is "twenty billion, four hundred forty-seven million, two hundred thirty-one thousand, nine hundred ninety-three".