20423351 has 4 divisors (see below), whose sum is σ = 21994392. Its totient is φ = 18852312.

The previous prime is 20423329. The next prime is 20423353. The reversal of 20423351 is 15332402.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20423351 is a prime.

It is a super-2 number, since 2×20423351² = 834226532138402, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20423353) 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, 785501 + ... + 785526.

It is an arithmetic number, because the mean of its divisors is an integer number (5498598).

Almost surely, 2^20423351 is an apocalyptic number.

20423351 is a deficient number, since it is larger than the sum of its proper divisors (1571041).

20423351 is a wasteful number, since it uses less digits than its factorization.

20423351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1571040.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 20423351 is about 4519.2201760923. The cubic root of 20423351 is about 273.3436569899.

Adding to 20423351 its reverse (15332402), we get a palindrome (35755753).

The spelling of 20423351 in words is "twenty million, four hundred twenty-three thousand, three hundred fifty-one".