20057321 has 4 divisors (see below), whose sum is σ = 20356752. Its totient is φ = 19757892.

The previous prime is 20057291. The next prime is 20057347. The reversal of 20057321 is 12375002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12375002 = 2 ⋅6187501.

It is a cyclic number.

It is not a de Polignac number, because 20057321 - 2¹⁰ = 20056297 is a prime.

It is a super-2 number, since 2×20057321² = 804592251394082, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20057293 and 20057302.

It is not an unprimeable number, because it can be changed into a prime (20057351) 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 3 ways as a sum of consecutive naturals, for example, 149615 + ... + 149748.

It is an arithmetic number, because the mean of its divisors is an integer number (5089188).

Almost surely, 2^20057321 is an apocalyptic number.

It is an amenable number.

20057321 is a deficient number, since it is larger than the sum of its proper divisors (299431).

20057321 is an equidigital number, since it uses as much as digits as its factorization.

20057321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299430.

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 20057321 is about 4478.5400522938. The cubic root of 20057321 is about 271.7008361970.

The spelling of 20057321 in words is "twenty million, fifty-seven thousand, three hundred twenty-one".