91047949 has 4 divisors (see below), whose sum is σ = 91115260. Its totient is φ = 90980640.

The previous prime is 91047947. The next prime is 91047959. The reversal of 91047949 is 94974019.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35022724 + 56025225 = 5918^2 + 7485^2 .

It is a cyclic number.

It is not a de Polignac number, because 91047949 - 2¹ = 91047947 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 (91047941) 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, 31584 + ... + 34345.

It is an arithmetic number, because the mean of its divisors is an integer number (22778815).

Almost surely, 2^91047949 is an apocalyptic number.

It is an amenable number.

91047949 is a deficient number, since it is larger than the sum of its proper divisors (67311).

91047949 is a wasteful number, since it uses less digits than its factorization.

91047949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67310.

The product of its (nonzero) digits is 81648, while the sum is 43.

The square root of 91047949 is about 9541.9048936782. The cubic root of 91047949 is about 449.8731313134.

The spelling of 91047949 in words is "ninety-one million, forty-seven thousand, nine hundred forty-nine".