28091986 has 16 divisors (see below), whose sum is σ = 46436544. Its totient is φ = 12663504.

The previous prime is 28091977. The next prime is 28092023. The reversal of 28091986 is 68919082.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11446 + ... + 13681.

It is an arithmetic number, because the mean of its divisors is an integer number (2902284).

Almost surely, 2^28091986 is an apocalyptic number.

28091986 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

28091986 is a deficient number, since it is larger than the sum of its proper divisors (18344558).

28091986 is a wasteful number, since it uses less digits than its factorization.

28091986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25185.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 28091986 is about 5300.1873551791. The cubic root of 28091986 is about 303.9910618909.

The spelling of 28091986 in words is "twenty-eight million, ninety-one thousand, nine hundred eighty-six".