28621777 has 4 divisors (see below), whose sum is σ = 28943460. Its totient is φ = 28300096.

The previous prime is 28621763. The next prime is 28621783. The reversal of 28621777 is 77712682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 77712682 = 2 ⋅38856341.

It can be written as a sum of positive squares in 2 ways, for example, as 17338896 + 11282881 = 4164^2 + 3359^2 .

It is a cyclic number.

It is not a de Polignac number, because 28621777 - 2¹¹ = 28619729 is a prime.

It is a super-2 number, since 2×28621777² = 1638412237275458, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28621717) 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, 160708 + ... + 160885.

It is an arithmetic number, because the mean of its divisors is an integer number (7235865).

Almost surely, 2^28621777 is an apocalyptic number.

It is an amenable number.

28621777 is a deficient number, since it is larger than the sum of its proper divisors (321683).

28621777 is an equidigital number, since it uses as much as digits as its factorization.

28621777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321682.

The product of its digits is 65856, while the sum is 40.

The square root of 28621777 is about 5349.9324294798. The cubic root of 28621777 is about 305.8901773154.

The spelling of 28621777 in words is "twenty-eight million, six hundred twenty-one thousand, seven hundred seventy-seven".