28156305 has 8 divisors (see below), whose sum is σ = 45050112. Its totient is φ = 15016688.

The previous prime is 28156279. The next prime is 28156321. The reversal of 28156305 is 50365182.

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 28156305 - 2⁶ = 28156241 is a prime.

It is a super-2 number, since 2×28156305² = 1585555022506050, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 938529 + ... + 938558.

It is an arithmetic number, because the mean of its divisors is an integer number (5631264).

Almost surely, 2^28156305 is an apocalyptic number.

It is an amenable number.

28156305 is a deficient number, since it is larger than the sum of its proper divisors (16893807).

28156305 is a wasteful number, since it uses less digits than its factorization.

28156305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1877095.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 28156305 is about 5306.2515017666. The cubic root of 28156305 is about 304.2228895465. Note that the first 3 decimals are identical.

The spelling of 28156305 in words is "twenty-eight million, one hundred fifty-six thousand, three hundred five".