91821345 has 96 divisors (see below), whose sum is σ = 191673216. Its totient is φ = 37094400.

The previous prime is 91821343. The next prime is 91821347. The reversal of 91821345 is 54312819.

It is an interprime number because it is at equal distance from previous prime (91821343) and next prime (91821347).

It is not a de Polignac number, because 91821345 - 2¹ = 91821343 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91821343) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 331347 + ... + 331623.

It is an arithmetic number, because the mean of its divisors is an integer number (1996596).

Almost surely, 2^91821345 is an apocalyptic number.

It is an amenable number.

91821345 is an abundant number, since it is smaller than the sum of its proper divisors (99851871).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91821345 is a wasteful number, since it uses less digits than its factorization.

91821345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351 (or 344 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 91821345 is about 9582.3454853183. The cubic root of 91821345 is about 451.1433395084.

The spelling of 91821345 in words is "ninety-one million, eight hundred twenty-one thousand, three hundred forty-five".