20215245 has 16 divisors (see below), whose sum is σ = 32470272. Its totient is φ = 10739520.

The previous prime is 20215241. The next prime is 20215267. The reversal of 20215245 is 54251202.

It is a happy number.

It is not a de Polignac number, because 20215245 - 2² = 20215241 is a prime.

It is a super-2 number, since 2×20215245² = 817312260820050, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20215241) 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, 1579 + ... + 6551.

It is an arithmetic number, because the mean of its divisors is an integer number (2029392).

Almost surely, 2^20215245 is an apocalyptic number.

It is an amenable number.

20215245 is a deficient number, since it is larger than the sum of its proper divisors (12255027).

20215245 is a wasteful number, since it uses less digits than its factorization.

20215245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5252.

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 20215245 is about 4496.1366749689. The cubic root of 20215245 is about 272.4120637618.

Adding to 20215245 its reverse (54251202), we get a palindrome (74466447).

The spelling of 20215245 in words is "twenty million, two hundred fifteen thousand, two hundred forty-five".