20812249 has 4 divisors (see below), whose sum is σ = 21006864. Its totient is φ = 20617636.

The previous prime is 20812247. The next prime is 20812271. The reversal of 20812249 is 94221802.

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: 94221802 = 2 ⋅47110901.

It is a cyclic number.

It is not a de Polignac number, because 20812249 - 2¹ = 20812247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20812247) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97147 + ... + 97360.

It is an arithmetic number, because the mean of its divisors is an integer number (5251716).

Almost surely, 2^20812249 is an apocalyptic number.

It is an amenable number.

20812249 is a deficient number, since it is larger than the sum of its proper divisors (194615).

20812249 is a wasteful number, since it uses less digits than its factorization.

20812249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194614.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 20812249 is about 4562.0443882102. The cubic root of 20812249 is about 275.0677474961.

The spelling of 20812249 in words is "twenty million, eight hundred twelve thousand, two hundred forty-nine".