28047961 has 4 divisors (see below), whose sum is σ = 28806052. Its totient is φ = 27289872.

The previous prime is 28047949. The next prime is 28047973. The reversal of 28047961 is 16974082.

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

It is an interprime number because it is at equal distance from previous prime (28047949) and next prime (28047973).

It can be written as a sum of positive squares in 2 ways, for example, as 21576025 + 6471936 = 4645^2 + 2544^2 .

It is a cyclic number.

It is not a de Polignac number, because 28047961 - 2¹⁵ = 28015193 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 758053 = 28047961 / (2 + 8 + 0 + 4 + 7 + 9 + 6 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28047961.

It is not an unprimeable number, because it can be changed into a prime (28047991) 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, 378990 + ... + 379063.

It is an arithmetic number, because the mean of its divisors is an integer number (7201513).

Almost surely, 2^28047961 is an apocalyptic number.

It is an amenable number.

28047961 is a deficient number, since it is larger than the sum of its proper divisors (758091).

28047961 is an equidigital number, since it uses as much as digits as its factorization.

28047961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758090.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 28047961 is about 5296.0325716521. The cubic root of 28047961 is about 303.8321766741.

The spelling of 28047961 in words is "twenty-eight million, forty-seven thousand, nine hundred sixty-one".