20520842 has 8 divisors (see below), whose sum is σ = 30977796. Its totient is φ = 10194912.

The previous prime is 20520833. The next prime is 20520859. The reversal of 20520842 is 24802502.

It can be written as a sum of positive squares in 2 ways, for example, as 20241001 + 279841 = 4499^2 + 529^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×20520842² = 842209912777928, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32363 + ... + 32990.

Almost surely, 2^20520842 is an apocalyptic number.

20520842 is a deficient number, since it is larger than the sum of its proper divisors (10456954).

20520842 is a wasteful number, since it uses less digits than its factorization.

20520842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65512.

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 20520842 is about 4529.9935982295. The cubic root of 20520842 is about 273.7779026763. Note that the first 3 decimals are identical.

The spelling of 20520842 in words is "twenty million, five hundred twenty thousand, eight hundred forty-two".