28399261 has 8 divisors (see below), whose sum is σ = 31028544. Its totient is φ = 25777920.

The previous prime is 28399253. The next prime is 28399279. The reversal of 28399261 is 16299382.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 28399261 - 2³ = 28399253 is a prime.

It is a super-2 number, since 2×28399261² = 1613036050692242, 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 (28399201) 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, 7485 + ... + 10621.

It is an arithmetic number, because the mean of its divisors is an integer number (3878568).

Almost surely, 2^28399261 is an apocalyptic number.

It is an amenable number.

28399261 is a deficient number, since it is larger than the sum of its proper divisors (2629283).

28399261 is a wasteful number, since it uses less digits than its factorization.

28399261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3971.

The product of its digits is 46656, while the sum is 40.

The square root of 28399261 is about 5329.0957018992. The cubic root of 28399261 is about 305.0954140253.

It can be divided in two parts, 2839 and 9261, that added together give a square (12100 = 110²).

The spelling of 28399261 in words is "twenty-eight million, three hundred ninety-nine thousand, two hundred sixty-one".