28621081 has 8 divisors (see below), whose sum is σ = 30528360. Its totient is φ = 26738688.

The previous prime is 28621079. The next prime is 28621093. The reversal of 28621081 is 18012682.

It can be written as a sum of positive squares in 4 ways, for example, as 13286025 + 15335056 = 3645^2 + 3916^2 .

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

It is not a de Polignac number, because 28621081 - 2¹ = 28621079 is a prime.

It is a super-2 number, since 2×28621081² = 1638332555217122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28625081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3816 + ... + 8473.

It is an arithmetic number, because the mean of its divisors is an integer number (3816045).

Almost surely, 2^28621081 is an apocalyptic number.

It is an amenable number.

28621081 is a deficient number, since it is larger than the sum of its proper divisors (1907279).

28621081 is a wasteful number, since it uses less digits than its factorization.

28621081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12443.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 28621081 is about 5349.8673815339. The cubic root of 28621081 is about 305.8876978363.

The spelling of 28621081 in words is "twenty-eight million, six hundred twenty-one thousand, eighty-one".