20825215 has 4 divisors (see below), whose sum is σ = 24990264. Its totient is φ = 16660168.

The previous prime is 20825209. The next prime is 20825227. The reversal of 20825215 is 51252802.

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

It is a cyclic number.

It is not a de Polignac number, because 20825215 - 2¹¹ = 20823167 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20825215.

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, 2082517 + ... + 2082526.

It is an arithmetic number, because the mean of its divisors is an integer number (6247566).

Almost surely, 2^20825215 is an apocalyptic number.

20825215 is a deficient number, since it is larger than the sum of its proper divisors (4165049).

20825215 is an equidigital number, since it uses as much as digits as its factorization.

20825215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4165048.

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 20825215 is about 4563.4652403629. The cubic root of 20825215 is about 275.1248579029.

The spelling of 20825215 in words is "twenty million, eight hundred twenty-five thousand, two hundred fifteen".