91217253 has 4 divisors (see below), whose sum is σ = 121623008. Its totient is φ = 60811500.

The previous prime is 91217239. The next prime is 91217281. The reversal of 91217253 is 35271219.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 35271219 = 3 ⋅11757073.

It is not a de Polignac number, because 91217253 - 2²⁶ = 24108389 is a prime.

It is a super-3 number, since 3×91217253³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 91217253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91217653) 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, 15202873 + ... + 15202878.

It is an arithmetic number, because the mean of its divisors is an integer number (30405752).

Almost surely, 2^91217253 is an apocalyptic number.

It is an amenable number.

91217253 is a deficient number, since it is larger than the sum of its proper divisors (30405755).

91217253 is a wasteful number, since it uses less digits than its factorization.

91217253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30405754.

The product of its digits is 3780, while the sum is 30.

The square root of 91217253 is about 9550.7723771431. The cubic root of 91217253 is about 450.1518055734.

The spelling of 91217253 in words is "ninety-one million, two hundred seventeen thousand, two hundred fifty-three".