20090842 has 4 divisors (see below), whose sum is σ = 30136266. Its totient is φ = 10045420.

The previous prime is 20090839. The next prime is 20090843. The reversal of 20090842 is 24809002.

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

It can be written as a sum of positive squares in only one way, i.e., 13845841 + 6245001 = 3721^2 + 2499^2 .

It is not an unprimeable number, because it can be changed into a prime (20090843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5022709 + ... + 5022712.

Almost surely, 2^20090842 is an apocalyptic number.

20090842 is a deficient number, since it is larger than the sum of its proper divisors (10045424).

20090842 is a wasteful number, since it uses less digits than its factorization.

20090842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10045423.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 20090842 is about 4482.2808925814. The cubic root of 20090842 is about 271.8521128750.

Adding to 20090842 its reverse (24809002), we get a palindrome (44899844).

The spelling of 20090842 in words is "twenty million, ninety thousand, eight hundred forty-two".