91563321 has 4 divisors (see below), whose sum is σ = 122084432. Its totient is φ = 61042212.

The previous prime is 91563319. The next prime is 91563323. The reversal of 91563321 is 12336519.

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.

It is an interprime number because it is at equal distance from previous prime (91563319) and next prime (91563323).

It is not a de Polignac number, because 91563321 - 2¹ = 91563319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91563323) 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, 15260551 + ... + 15260556.

It is an arithmetic number, because the mean of its divisors is an integer number (30521108).

Almost surely, 2^91563321 is an apocalyptic number.

It is an amenable number.

91563321 is a deficient number, since it is larger than the sum of its proper divisors (30521111).

91563321 is a wasteful number, since it uses less digits than its factorization.

91563321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30521110.

The product of its digits is 4860, while the sum is 30.

The square root of 91563321 is about 9568.8725041146. The cubic root of 91563321 is about 450.7203622745.

The spelling of 91563321 in words is "ninety-one million, five hundred sixty-three thousand, three hundred twenty-one".