91969813 has 8 divisors (see below), whose sum is σ = 104870808. Its totient is φ = 79901184.

The previous prime is 91969807. The next prime is 91969831. The reversal of 91969813 is 31896919.

It can be written as a sum of positive squares in 4 ways, for example, as 34316164 + 57653649 = 5858^2 + 7593^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 91969813 - 2⁹ = 91969301 is a prime.

It is a super-3 number, since 3×91969813³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91964813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 207856 + ... + 208297.

It is an arithmetic number, because the mean of its divisors is an integer number (13108851).

Almost surely, 2^91969813 is an apocalyptic number.

It is an amenable number.

91969813 is a deficient number, since it is larger than the sum of its proper divisors (12900995).

91969813 is a wasteful number, since it uses less digits than its factorization.

91969813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416183.

The product of its digits is 104976, while the sum is 46.

The square root of 91969813 is about 9590.0893113672. The cubic root of 91969813 is about 451.3863631795.

The spelling of 91969813 in words is "ninety-one million, nine hundred sixty-nine thousand, eight hundred thirteen".