28390261 has 8 divisors (see below), whose sum is σ = 28711584. Its totient is φ = 28071120.

The previous prime is 28390259. The next prime is 28390267. The reversal of 28390261 is 16209382.

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 28390261 - 2¹ = 28390259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28390267) 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, 41226 + ... + 41908.

It is an arithmetic number, because the mean of its divisors is an integer number (3588948).

Almost surely, 2^28390261 is an apocalyptic number.

It is an amenable number.

28390261 is a deficient number, since it is larger than the sum of its proper divisors (321323).

28390261 is a wasteful number, since it uses less digits than its factorization.

28390261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1091.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 28390261 is about 5328.2512140476. The cubic root of 28390261 is about 305.0631813927.

The spelling of 28390261 in words is "twenty-eight million, three hundred ninety thousand, two hundred sixty-one".