91689788 has 12 divisors (see below), whose sum is σ = 163485000. Its totient is φ = 44979792.

The previous prime is 91689779. The next prime is 91689791. The reversal of 91689788 is 88798619.

It is a happy number.

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, 216038 + ... + 216461.

It is an arithmetic number, because the mean of its divisors is an integer number (13623750).

Almost surely, 2^91689788 is an apocalyptic number.

It is an amenable number.

91689788 is a deficient number, since it is larger than the sum of its proper divisors (71795212).

91689788 is a wasteful number, since it uses less digits than its factorization.

91689788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432556 (or 432554 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 56.

The square root of 91689788 is about 9575.4784736847. The cubic root of 91689788 is about 450.9277780396.

The spelling of 91689788 in words is "ninety-one million, six hundred eighty-nine thousand, seven hundred eighty-eight".