28783551 has 4 divisors (see below), whose sum is σ = 38378072. Its totient is φ = 19189032.

The previous prime is 28783549. The next prime is 28783553. The reversal of 28783551 is 15538782.

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

It is an interprime number because it is at equal distance from previous prime (28783549) and next prime (28783553).

It is not a de Polignac number, because 28783551 - 2¹ = 28783549 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 (28783553) 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, 4797256 + ... + 4797261.

It is an arithmetic number, because the mean of its divisors is an integer number (9594518).

Almost surely, 2^28783551 is an apocalyptic number.

28783551 is a deficient number, since it is larger than the sum of its proper divisors (9594521).

28783551 is an equidigital number, since it uses as much as digits as its factorization.

28783551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9594520.

The product of its digits is 67200, while the sum is 39.

The square root of 28783551 is about 5365.0303820202. The cubic root of 28783551 is about 306.4654052519.

It can be divided in two parts, 287 and 83551, that added together give a palindrome (83838).

The spelling of 28783551 in words is "twenty-eight million, seven hundred eighty-three thousand, five hundred fifty-one".