28206722 has 4 divisors (see below), whose sum is σ = 42310086. Its totient is φ = 14103360.

The previous prime is 28206707. The next prime is 28206749. The reversal of 28206722 is 22760282.

It is a Cunningham number, because it is equal to 5311²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 22760282 = 2 ⋅11380141.

It can be written as a sum of positive squares in only one way, i.e., 28206721 + 1 = 5311^2 + 1^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7051679 + ... + 7051682.

Almost surely, 2^28206722 is an apocalyptic number.

28206722 is a deficient number, since it is larger than the sum of its proper divisors (14103364).

28206722 is a wasteful number, since it uses less digits than its factorization.

28206722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14103363.

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 28206722 is about 5311.0000941442. Note that the first 4 decimals coincide. The cubic root of 28206722 is about 304.4043629290.

The spelling of 28206722 in words is "twenty-eight million, two hundred six thousand, seven hundred twenty-two".