28921315 has 4 divisors (see below), whose sum is σ = 34705584. Its totient is φ = 23137048.

The previous prime is 28921307. The next prime is 28921337. The reversal of 28921315 is 51312982.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28921315 - 2³ = 28921307 is a prime.

It is a super-2 number, since 2×28921315² = 1672884922658450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2892127 + ... + 2892136.

It is an arithmetic number, because the mean of its divisors is an integer number (8676396).

Almost surely, 2^28921315 is an apocalyptic number.

28921315 is a deficient number, since it is larger than the sum of its proper divisors (5784269).

28921315 is an equidigital number, since it uses as much as digits as its factorization.

28921315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5784268.

The product of its digits is 4320, while the sum is 31.

The square root of 28921315 is about 5377.8541259502. The cubic root of 28921315 is about 306.9535627753.

The spelling of 28921315 in words is "twenty-eight million, nine hundred twenty-one thousand, three hundred fifteen".