20452821 has 16 divisors (see below), whose sum is σ = 28047360. Its totient is φ = 13250160.

The previous prime is 20452811. The next prime is 20452829. The reversal of 20452821 is 12825402.

It is not a de Polignac number, because 20452821 - 2¹⁵ = 20420053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20452791 and 20452800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20452829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42460 + ... + 42938.

It is an arithmetic number, because the mean of its divisors is an integer number (1752960).

Almost surely, 2^20452821 is an apocalyptic number.

It is an amenable number.

20452821 is a deficient number, since it is larger than the sum of its proper divisors (7594539).

20452821 is a wasteful number, since it uses less digits than its factorization.

20452821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856.

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 20452821 is about 4522.4795190249. The cubic root of 20452821 is about 273.4750681073.

The spelling of 20452821 in words is "twenty million, four hundred fifty-two thousand, eight hundred twenty-one".