28422781 has 4 divisors (see below), whose sum is σ = 28481632. Its totient is φ = 28363932.

The previous prime is 28422763. The next prime is 28422811. The reversal of 28422781 is 18722482.

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 28422781 - 2⁵ = 28422749 is a prime.

It is a super-2 number, since 2×28422781² = 1615708959547922, 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 (28422701) 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, 28695 + ... + 29668.

It is an arithmetic number, because the mean of its divisors is an integer number (7120408).

Almost surely, 2^28422781 is an apocalyptic number.

It is an amenable number.

28422781 is a deficient number, since it is larger than the sum of its proper divisors (58851).

28422781 is an equidigital number, since it uses as much as digits as its factorization.

28422781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58850.

The product of its digits is 14336, while the sum is 34.

The square root of 28422781 is about 5331.3019985741. The cubic root of 28422781 is about 305.1796164988.

The spelling of 28422781 in words is "twenty-eight million, four hundred twenty-two thousand, seven hundred eighty-one".