91751986 has 4 divisors (see below), whose sum is σ = 137627982. Its totient is φ = 45875992.

The previous prime is 91751963. The next prime is 91751987. The reversal of 91751986 is 68915719.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68915719 = 37 ⋅1862587.

It can be written as a sum of positive squares in only one way, i.e., 90839961 + 912025 = 9531^2 + 955^2 .

It is not an unprimeable number, because it can be changed into a prime (91751987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22937995 + ... + 22937998.

Almost surely, 2^91751986 is an apocalyptic number.

91751986 is a deficient number, since it is larger than the sum of its proper divisors (45875996).

91751986 is a wasteful number, since it uses less digits than its factorization.

91751986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45875995.

The product of its digits is 136080, while the sum is 46.

The square root of 91751986 is about 9578.7256981292. The cubic root of 91751986 is about 451.0297176597.

The spelling of 91751986 in words is "ninety-one million, seven hundred fifty-one thousand, nine hundred eighty-six".