20321890 has 16 divisors (see below), whose sum is σ = 36653760. Its totient is φ = 8112240.

The previous prime is 20321879. The next prime is 20321893. The reversal of 20321890 is 9812302.

It is not an unprimeable number, because it can be changed into a prime (20321893) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 3931 + ... + 7489.

It is an arithmetic number, because the mean of its divisors is an integer number (2290860).

Almost surely, 2^20321890 is an apocalyptic number.

20321890 is a deficient number, since it is larger than the sum of its proper divisors (16331870).

20321890 is a wasteful number, since it uses less digits than its factorization.

20321890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4137.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 20321890 is about 4507.9807009347. The cubic root of 20321890 is about 272.8902581003.

The spelling of 20321890 in words is "twenty million, three hundred twenty-one thousand, eight hundred ninety".