20353391 has 4 divisors (see below), whose sum is σ = 21009984. Its totient is φ = 19696800.

The previous prime is 20353387. The next prime is 20353393. The reversal of 20353391 is 19335302.

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 20353391 - 2² = 20353387 is a prime.

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 20353391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20353393) 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, 328250 + ... + 328311.

It is an arithmetic number, because the mean of its divisors is an integer number (5252496).

Almost surely, 2^20353391 is an apocalyptic number.

20353391 is a deficient number, since it is larger than the sum of its proper divisors (656593).

20353391 is an equidigital number, since it uses as much as digits as its factorization.

20353391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656592.

The product of its (nonzero) digits is 2430, while the sum is 26.

The square root of 20353391 is about 4511.4732626937. The cubic root of 20353391 is about 273.0311878747.

Adding to 20353391 its reverse (19335302), we get a palindrome (39688693).

The spelling of 20353391 in words is "twenty million, three hundred fifty-three thousand, three hundred ninety-one".