91239986 has 8 divisors (see below), whose sum is σ = 144910620. Its totient is φ = 42936448.

The previous prime is 91239983. The next prime is 91239989. The reversal of 91239986 is 68993219.

It is an interprime number because it is at equal distance from previous prime (91239983) and next prime (91239989).

It can be written as a sum of positive squares in 2 ways, for example, as 90916225 + 323761 = 9535^2 + 569^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 91239986.

It is not an unprimeable number, because it can be changed into a prime (91239983) 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, 1341731 + ... + 1341798.

Almost surely, 2^91239986 is an apocalyptic number.

91239986 is a deficient number, since it is larger than the sum of its proper divisors (53670634).

91239986 is a wasteful number, since it uses less digits than its factorization.

91239986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2683548.

The product of its digits is 209952, while the sum is 47.

The square root of 91239986 is about 9551.9624161740. The cubic root of 91239986 is about 450.1891978089.

The spelling of 91239986 in words is "ninety-one million, two hundred thirty-nine thousand, nine hundred eighty-six".