91649 has 4 divisors (see below), whose sum is σ = 94164. Its totient is φ = 89136.

The previous prime is 91639. The next prime is 91673. The reversal of 91649 is 94619.

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 66049 + 25600 = 257^2 + 160^2 .

It is a cyclic number.

It is not a de Polignac number, because 91649 - 2⁸ = 91393 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91639) 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, 1202 + ... + 1275.

It is an arithmetic number, because the mean of its divisors is an integer number (23541).

It is a Proth number, since it is equal to 179 ⋅ 2⁹ + 1 and 179 < 2⁹.

2⁹¹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

91649 is a deficient number, since it is larger than the sum of its proper divisors (2515).

91649 is a wasteful number, since it uses less digits than its factorization.

91649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2514.

The product of its digits is 1944, while the sum is 29.

The square root of 91649 is about 302.7358584641. The cubic root of 91649 is about 45.0860903380.

It can be divided in two parts, 9 and 1649, that multiplied together give a palindrome (14841).

The spelling of 91649 in words is "ninety-one thousand, six hundred forty-nine".