91781253 has 6 divisors (see below), whose sum is σ = 132572934. Its totient is φ = 61187496.

The previous prime is 91781251. The next prime is 91781257. The reversal of 91781253 is 35218719.

It can be written as a sum of positive squares in only one way, i.e., 47983329 + 43797924 = 6927^2 + 6618^2 .

It is not a de Polignac number, because 91781253 - 2¹ = 91781251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91781251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5098950 + ... + 5098967.

It is an arithmetic number, because the mean of its divisors is an integer number (22095489).

Almost surely, 2^91781253 is an apocalyptic number.

It is an amenable number.

91781253 is a deficient number, since it is larger than the sum of its proper divisors (40791681).

91781253 is a wasteful number, since it uses less digits than its factorization.

91781253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10197923 (or 10197920 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 91781253 is about 9580.2532847519. The cubic root of 91781253 is about 451.0776689685.

The spelling of 91781253 in words is "ninety-one million, seven hundred eighty-one thousand, two hundred fifty-three".