91306221 has 8 divisors (see below), whose sum is σ = 124711104. Its totient is φ = 59386080.

The previous prime is 91306219. The next prime is 91306223. The reversal of 91306221 is 12260319.

It is an interprime number because it is at equal distance from previous prime (91306219) and next prime (91306223).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91306221 - 2¹ = 91306219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91306191 and 91306200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91306223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 371041 + ... + 371286.

It is an arithmetic number, because the mean of its divisors is an integer number (15588888).

Almost surely, 2^91306221 is an apocalyptic number.

It is an amenable number.

91306221 is a deficient number, since it is larger than the sum of its proper divisors (33404883).

91306221 is a wasteful number, since it uses less digits than its factorization.

91306221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742371.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 91306221 is about 9555.4288757753. The cubic root of 91306221 is about 450.2981086431.

It can be divided in two parts, 9130 and 6221, that added together give a palindrome (15351).

The spelling of 91306221 in words is "ninety-one million, three hundred six thousand, two hundred twenty-one".