28122261 has 24 divisors (see below), whose sum is σ = 41330880. Its totient is φ = 16974144.

The previous prime is 28122253. The next prime is 28122271. The reversal of 28122261 is 16222182.

It is not a de Polignac number, because 28122261 - 2³ = 28122253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28122221) 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 23 ways as a sum of consecutive naturals, for example, 24345 + ... + 25473.

It is an arithmetic number, because the mean of its divisors is an integer number (1722120).

Almost surely, 2^28122261 is an apocalyptic number.

It is an amenable number.

28122261 is a deficient number, since it is larger than the sum of its proper divisors (13208619).

28122261 is a wasteful number, since it uses less digits than its factorization.

28122261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1193 (or 1174 counting only the distinct ones).

The product of its digits is 768, while the sum is 24.

The square root of 28122261 is about 5303.0426172151. The cubic root of 28122261 is about 304.1002273685.

The spelling of 28122261 in words is "twenty-eight million, one hundred twenty-two thousand, two hundred sixty-one".