28962781 has 4 divisors (see below), whose sum is σ = 30666492. Its totient is φ = 27259072.

The previous prime is 28962719. The next prime is 28962797. The reversal of 28962781 is 18726982.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19096900 + 9865881 = 4370^2 + 3141^2 .

It is a cyclic number.

It is not a de Polignac number, because 28962781 - 2¹¹ = 28960733 is a prime.

It is a super-2 number, since 2×28962781² = 1677685366507922, 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 (28962701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 851830 + ... + 851863.

It is an arithmetic number, because the mean of its divisors is an integer number (7666623).

Almost surely, 2^28962781 is an apocalyptic number.

It is an amenable number.

28962781 is a deficient number, since it is larger than the sum of its proper divisors (1703711).

28962781 is a wasteful number, since it uses less digits than its factorization.

28962781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1703710.

The product of its digits is 96768, while the sum is 43.

The square root of 28962781 is about 5381.7080002542. The cubic root of 28962781 is about 307.1001911735.

The spelling of 28962781 in words is "twenty-eight million, nine hundred sixty-two thousand, seven hundred eighty-one".