20031321 has 16 divisors (see below), whose sum is σ = 29510784. Its totient is φ = 12021504.

The previous prime is 20031313. The next prime is 20031331. The reversal of 20031321 is 12313002.

It is a happy number.

It is not a de Polignac number, because 20031321 - 2³ = 20031313 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20031297 and 20031306.

It is not an unprimeable number, because it can be changed into a prime (20031311) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 7366 + ... + 9711.

It is an arithmetic number, because the mean of its divisors is an integer number (1844424).

Almost surely, 2^20031321 is an apocalyptic number.

It is an amenable number.

20031321 is a deficient number, since it is larger than the sum of its proper divisors (9479463).

20031321 is a wasteful number, since it uses less digits than its factorization.

20031321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17120.

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 20031321 is about 4475.6363793320. The cubic root of 20031321 is about 271.5833848791.

Subtracting from 20031321 its product of nonzero digits (36), we obtain a triangular number (20031285 = T₆₃₂₉).

Adding to 20031321 its reverse (12313002), we get a palindrome (32344323).

The spelling of 20031321 in words is "twenty million, thirty-one thousand, three hundred twenty-one".