91787690 has 8 divisors (see below), whose sum is σ = 165217860. Its totient is φ = 36715072.

The previous prime is 91787681. The next prime is 91787693. The reversal of 91787690 is 9678719.

It can be written as a sum of positive squares in 2 ways, for example, as 87815641 + 3972049 = 9371^2 + 1993^2 .

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

It is a super-2 number, since 2×91787690² = 16849960071072200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91787693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4589375 + ... + 4589394.

Almost surely, 2^91787690 is an apocalyptic number.

91787690 is a deficient number, since it is larger than the sum of its proper divisors (73430170).

91787690 is a wasteful number, since it uses less digits than its factorization.

91787690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9178776.

The product of its (nonzero) digits is 190512, while the sum is 47.

The square root of 91787690 is about 9580.5892303136. The cubic root of 91787690 is about 451.0882140380.

The spelling of 91787690 in words is "ninety-one million, seven hundred eighty-seven thousand, six hundred ninety".