20123391 has 8 divisors (see below), whose sum is σ = 26866944. Its totient is φ = 13397720.

The previous prime is 20123387. The next prime is 20123401. The reversal of 20123391 is 19332102.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20123391 - 2² = 20123387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1575 + ... + 6536.

It is an arithmetic number, because the mean of its divisors is an integer number (3358368).

Almost surely, 2^20123391 is an apocalyptic number.

20123391 is a deficient number, since it is larger than the sum of its proper divisors (6743553).

20123391 is an equidigital number, since it uses as much as digits as its factorization.

20123391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8941.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 20123391 is about 4485.9102755182. The cubic root of 20123391 is about 271.9988420871.

Adding to 20123391 its reverse (19332102), we get a palindrome (39455493).

The spelling of 20123391 in words is "twenty million, one hundred twenty-three thousand, three hundred ninety-one".