20772217 has 4 divisors (see below), whose sum is σ = 20876800. Its totient is φ = 20667636.

The previous prime is 20772209. The next prime is 20772233. The reversal of 20772217 is 71227702.

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.

It is a cyclic number.

It is not a de Polignac number, because 20772217 - 2³ = 20772209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20772517) 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, 51993 + ... + 52390.

It is an arithmetic number, because the mean of its divisors is an integer number (5219200).

Almost surely, 2^20772217 is an apocalyptic number.

It is an amenable number.

20772217 is a deficient number, since it is larger than the sum of its proper divisors (104583).

20772217 is a wasteful number, since it uses less digits than its factorization.

20772217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104582.

The product of its (nonzero) digits is 2744, while the sum is 28.

The square root of 20772217 is about 4557.6547697253. The cubic root of 20772217 is about 274.8912716176.

Adding to 20772217 its reverse (71227702), we get a palindrome (91999919).

The spelling of 20772217 in words is "twenty million, seven hundred seventy-two thousand, two hundred seventeen".