20021245 has 4 divisors (see below), whose sum is σ = 24025500. Its totient is φ = 16016992.

The previous prime is 20021233. The next prime is 20021251. The reversal of 20021245 is 54212002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8173881 + 11847364 = 2859^2 + 3442^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021245 - 2⁵ = 20021213 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2002120 + ... + 2002129.

It is an arithmetic number, because the mean of its divisors is an integer number (6006375).

Almost surely, 2^20021245 is an apocalyptic number.

It is an amenable number.

20021245 is a deficient number, since it is larger than the sum of its proper divisors (4004255).

20021245 is an equidigital number, since it uses as much as digits as its factorization.

20021245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4004254.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 20021245 is about 4474.5105877626. The cubic root of 20021245 is about 271.5378406513.

Adding to 20021245 its reverse (54212002), we get a palindrome (74233247).

The spelling of 20021245 in words is "twenty million, twenty-one thousand, two hundred forty-five".