28135261 has 16 divisors (see below), whose sum is σ = 35798400. Its totient is φ = 21920640.

The previous prime is 28135231. The next prime is 28135277. The reversal of 28135261 is 16253182.

It is a de Polignac number, because none of the positive numbers 2^k-28135261 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28135231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45 + ... + 7501.

It is an arithmetic number, because the mean of its divisors is an integer number (2237400).

Almost surely, 2^28135261 is an apocalyptic number.

It is an amenable number.

28135261 is a deficient number, since it is larger than the sum of its proper divisors (7663139).

28135261 is an equidigital number, since it uses as much as digits as its factorization.

28135261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7489 (or 7475 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The square root of 28135261 is about 5304.2681870358. The cubic root of 28135261 is about 304.1470786744.

The spelling of 28135261 in words is "twenty-eight million, one hundred thirty-five thousand, two hundred sixty-one".