91009690 has 8 divisors (see below), whose sum is σ = 163817460. Its totient is φ = 36403872.

The previous prime is 91009679. The next prime is 91009693. The reversal of 91009690 is 9690019.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 86174089 + 4835601 = 9283^2 + 2199^2 .

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

It is a super-2 number, since 2×91009690² = 16565527347792200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91009693) 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, 4550475 + ... + 4550494.

Almost surely, 2^91009690 is an apocalyptic number.

91009690 is a deficient number, since it is larger than the sum of its proper divisors (72807770).

91009690 is a wasteful number, since it uses less digits than its factorization.

91009690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9100976.

The product of its (nonzero) digits is 4374, while the sum is 34.

The square root of 91009690 is about 9539.8998946530. The cubic root of 91009690 is about 449.8101091816.

The spelling of 91009690 in words is "ninety-one million, nine thousand, six hundred ninety".