91081901 has 8 divisors (see below), whose sum is σ = 94473624. Its totient is φ = 87739200.

The previous prime is 91081891. The next prime is 91081919. The reversal of 91081901 is 10918019.

It can be written as a sum of positive squares in 4 ways, for example, as 48636676 + 42445225 = 6974^2 + 6515^2 .

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 91081901 - 2¹⁴ = 91065517 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 (91081981) 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, 8450 + ... + 15923.

It is an arithmetic number, because the mean of its divisors is an integer number (11809203).

Almost surely, 2^91081901 is an apocalyptic number.

It is an amenable number.

91081901 is a deficient number, since it is larger than the sum of its proper divisors (3391723).

91081901 is a wasteful number, since it uses less digits than its factorization.

91081901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24511.

The product of its (nonzero) digits is 648, while the sum is 29.

The square root of 91081901 is about 9543.6838275375. The cubic root of 91081901 is about 449.9290439563.

The spelling of 91081901 in words is "ninety-one million, eighty-one thousand, nine hundred one".