91408813 has 8 divisors (see below), whose sum is σ = 97953408. Its totient is φ = 84993984.

The previous prime is 91408799. The next prime is 91408861. The reversal of 91408813 is 31880419.

It is a happy number.

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 91408813 - 2⁵ = 91408781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91408883) 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, 30981 + ... + 33802.

It is an arithmetic number, because the mean of its divisors is an integer number (12244176).

Almost surely, 2^91408813 is an apocalyptic number.

It is an amenable number.

91408813 is a deficient number, since it is larger than the sum of its proper divisors (6544595).

91408813 is a wasteful number, since it uses less digits than its factorization.

91408813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64883.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 91408813 is about 9560.7956258880. The cubic root of 91408813 is about 450.4666977107.

The spelling of 91408813 in words is "ninety-one million, four hundred eight thousand, eight hundred thirteen".