91287128 has 16 divisors (see below), whose sum is σ = 177066000. Its totient is φ = 44069536.

The previous prime is 91287109. The next prime is 91287137. The reversal of 91287128 is 82178219.

It is a junction number, because it is equal to n+sod(n) for n = 91287091 and 91287100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196508 + ... + 196971.

It is an arithmetic number, because the mean of its divisors is an integer number (11066625).

Almost surely, 2^91287128 is an apocalyptic number.

It is an amenable number.

91287128 is a deficient number, since it is larger than the sum of its proper divisors (85778872).

91287128 is a wasteful number, since it uses less digits than its factorization.

91287128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393514 (or 393510 counting only the distinct ones).

The product of its digits is 16128, while the sum is 38.

The square root of 91287128 is about 9554.4297579709. The cubic root of 91287128 is about 450.2667192480.

The spelling of 91287128 in words is "ninety-one million, two hundred eighty-seven thousand, one hundred twenty-eight".