28522781 has 8 divisors (see below), whose sum is σ = 34313280. Its totient is φ = 23161248.

The previous prime is 28522733. The next prime is 28522789. The reversal of 28522781 is 18722582.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28522781 is a prime.

It is a super-2 number, since 2×28522781² = 1627098071947922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28522789) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107096 + ... + 107361.

It is an arithmetic number, because the mean of its divisors is an integer number (4289160).

Almost surely, 2^28522781 is an apocalyptic number.

It is an amenable number.

28522781 is a deficient number, since it is larger than the sum of its proper divisors (5790499).

28522781 is a wasteful number, since it uses less digits than its factorization.

28522781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214483.

The product of its digits is 17920, while the sum is 35.

The square root of 28522781 is about 5340.6723359517. The cubic root of 28522781 is about 305.5371025232.

The spelling of 28522781 in words is "twenty-eight million, five hundred twenty-two thousand, seven hundred eighty-one".