28742109 has 16 divisors (see below), whose sum is σ = 41981760. Its totient is φ = 17346560.

The previous prime is 28742099. The next prime is 28742113. The reversal of 28742109 is 90124782.

It is a happy number.

It is not a de Polignac number, because 28742109 - 2⁴ = 28742093 is a prime.

It is a super-2 number, since 2×28742109² = 1652217659535762, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a self number, because there is not a number n which added to its sum of digits gives 28742109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28742179) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6787 + ... + 10175.

It is an arithmetic number, because the mean of its divisors is an integer number (2623860).

Almost surely, 2^28742109 is an apocalyptic number.

It is an amenable number.

28742109 is a deficient number, since it is larger than the sum of its proper divisors (13239651).

28742109 is a wasteful number, since it uses less digits than its factorization.

28742109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3660.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 28742109 is about 5361.1667573393. The cubic root of 28742109 is about 306.3182536197.

The spelling of 28742109 in words is "twenty-eight million, seven hundred forty-two thousand, one hundred nine".