91328643 has 12 divisors (see below), whose sum is σ = 150764848. Its totient is φ = 52187760.

The previous prime is 91328639. The next prime is 91328647. The reversal of 91328643 is 34682319.

91328643 is a `hidden beast` number, since 9 + 1 + 3 + 2 + 8 + 643 = 666.

It is an interprime number because it is at equal distance from previous prime (91328639) and next prime (91328647).

It is not a de Polignac number, because 91328643 - 2² = 91328639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91328598 and 91328607.

It is not an unprimeable number, because it can be changed into a prime (91328647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 724768 + ... + 724893.

Almost surely, 2^91328643 is an apocalyptic number.

91328643 is a deficient number, since it is larger than the sum of its proper divisors (59436205).

91328643 is a wasteful number, since it uses less digits than its factorization.

91328643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1449674 (or 1449671 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 91328643 is about 9556.6020634952. The cubic root of 91328643 is about 450.3349654155.

The spelling of 91328643 in words is "ninety-one million, three hundred twenty-eight thousand, six hundred forty-three".