28857551 has 4 divisors (see below), whose sum is σ = 30555072. Its totient is φ = 27160032.

The previous prime is 28857547. The next prime is 28857589. The reversal of 28857551 is 15575882.

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 28857551 - 2² = 28857547 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28857499 and 28857508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28853551) 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, 848735 + ... + 848768.

It is an arithmetic number, because the mean of its divisors is an integer number (7638768).

Almost surely, 2^28857551 is an apocalyptic number.

28857551 is a deficient number, since it is larger than the sum of its proper divisors (1697521).

28857551 is a wasteful number, since it uses less digits than its factorization.

28857551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1697520.

The product of its digits is 112000, while the sum is 41.

The square root of 28857551 is about 5371.9224677949. The cubic root of 28857551 is about 306.7278124504.

The spelling of 28857551 in words is "twenty-eight million, eight hundred fifty-seven thousand, five hundred fifty-one".