20342251 has 4 divisors (see below), whose sum is σ = 21538872. Its totient is φ = 19145632.

The previous prime is 20342249. The next prime is 20342269. The reversal of 20342251 is 15224302.

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 20342251 - 2¹ = 20342249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20342351) 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, 598285 + ... + 598318.

It is an arithmetic number, because the mean of its divisors is an integer number (5384718).

Almost surely, 2^20342251 is an apocalyptic number.

20342251 is a deficient number, since it is larger than the sum of its proper divisors (1196621).

20342251 is a wasteful number, since it uses less digits than its factorization.

20342251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1196620.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20342251 is about 4510.2384637622. The cubic root of 20342251 is about 272.9813661601.

Adding to 20342251 its reverse (15224302), we get a palindrome (35566553).

The spelling of 20342251 in words is "twenty million, three hundred forty-two thousand, two hundred fifty-one".