28782001 has 4 divisors (see below), whose sum is σ = 29394432. Its totient is φ = 28169572.

The previous prime is 28781971. The next prime is 28782031. The reversal of 28782001 is 10028782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (28781971) and next prime (28782031).

It is a cyclic number.

It is not a de Polignac number, because 28782001 - 2⁷ = 28781873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28782031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 306145 + ... + 306238.

It is an arithmetic number, because the mean of its divisors is an integer number (7348608).

Almost surely, 2^28782001 is an apocalyptic number.

It is an amenable number.

28782001 is a deficient number, since it is larger than the sum of its proper divisors (612431).

28782001 is an equidigital number, since it uses as much as digits as its factorization.

28782001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612430.

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 28782001 is about 5364.8859260939. The cubic root of 28782001 is about 306.4599040787.

The spelling of 28782001 in words is "twenty-eight million, seven hundred eighty-two thousand, one".