20342591 has 8 divisors (see below), whose sum is σ = 21584304. Its totient is φ = 19105920.

The previous prime is 20342573. The next prime is 20342611. The reversal of 20342591 is 19524302.

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 20342591 - 2⁶ = 20342527 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 20342591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20342501) 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, 10001 + ... + 11861.

It is an arithmetic number, because the mean of its divisors is an integer number (2698038).

Almost surely, 2^20342591 is an apocalyptic number.

20342591 is a deficient number, since it is larger than the sum of its proper divisors (1241713).

20342591 is a wasteful number, since it uses less digits than its factorization.

20342591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2521.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 20342591 is about 4510.2761556251. The cubic root of 20342591 is about 272.9828870201.

Adding to 20342591 its reverse (19524302), we get a palindrome (39866893).

The spelling of 20342591 in words is "twenty million, three hundred forty-two thousand, five hundred ninety-one".