28810261 has 8 divisors (see below), whose sum is σ = 29256920. Its totient is φ = 28366848.

The previous prime is 28810247. The next prime is 28810267. The reversal of 28810261 is 16201882.

It can be written as a sum of positive squares in 4 ways, for example, as 20196036 + 8614225 = 4494^2 + 2935^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28810261 is a prime.

It is a super-2 number, since 2×28810261² = 1660062277776242, 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 (28810267) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21565 + ... + 22861.

It is an arithmetic number, because the mean of its divisors is an integer number (3657115).

Almost surely, 2^28810261 is an apocalyptic number.

It is an amenable number.

28810261 is a deficient number, since it is larger than the sum of its proper divisors (446659).

28810261 is a wasteful number, since it uses less digits than its factorization.

28810261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1623.

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

The square root of 28810261 is about 5367.5190730914. The cubic root of 28810261 is about 306.5601718807.

The spelling of 28810261 in words is "twenty-eight million, eight hundred ten thousand, two hundred sixty-one".