20372231391 has 4 divisors (see below), whose sum is σ = 27162975192. Its totient is φ = 13581487592.

The previous prime is 20372231387. The next prime is 20372231423. The reversal of 20372231391 is 19313227302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20372231391 - 2² = 20372231387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20372231351) 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, 3395371896 + ... + 3395371901.

It is an arithmetic number, because the mean of its divisors is an integer number (6790743798).

Almost surely, 2^20372231391 is an apocalyptic number.

20372231391 is a deficient number, since it is larger than the sum of its proper divisors (6790743801).

20372231391 is an equidigital number, since it uses as much as digits as its factorization.

20372231391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6790743800.

The product of its (nonzero) digits is 13608, while the sum is 33.

Adding to 20372231391 its reverse (19313227302), we get a palindrome (39685458693).

The spelling of 20372231391 in words is "twenty billion, three hundred seventy-two million, two hundred thirty-one thousand, three hundred ninety-one".