20219842 has 4 divisors (see below), whose sum is σ = 30329766. Its totient is φ = 10109920.

The previous prime is 20219839. The next prime is 20219861. The reversal of 20219842 is 24891202.

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., 19280881 + 938961 = 4391^2 + 969^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20219842.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5054959 + ... + 5054962.

Almost surely, 2^20219842 is an apocalyptic number.

20219842 is a deficient number, since it is larger than the sum of its proper divisors (10109924).

20219842 is a wasteful number, since it uses less digits than its factorization.

20219842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10109923.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 20219842 is about 4496.6478625750. The cubic root of 20219842 is about 272.4327112705.

The spelling of 20219842 in words is "twenty million, two hundred nineteen thousand, eight hundred forty-two".