20840858 has 4 divisors (see below), whose sum is σ = 31261290. Its totient is φ = 10420428.

The previous prime is 20840839. The next prime is 20840873. The reversal of 20840858 is 85804802.

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., 20675209 + 165649 = 4547^2 + 407^2 .

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, 5210213 + ... + 5210216.

Almost surely, 2^20840858 is an apocalyptic number.

20840858 is a deficient number, since it is larger than the sum of its proper divisors (10420432).

20840858 is a wasteful number, since it uses less digits than its factorization.

20840858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10420431.

The product of its (nonzero) digits is 20480, while the sum is 35.

The square root of 20840858 is about 4565.1788573943. The cubic root of 20840858 is about 275.1937279561.

The spelling of 20840858 in words is "twenty million, eight hundred forty thousand, eight hundred fifty-eight".