91005623 has 2 divisors, whose sum is σ = 91005624. Its totient is φ = 91005622.

The previous prime is 91005617. The next prime is 91005647. The reversal of 91005623 is 32650019.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91005623 - 2²⁶ = 23896759 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91005592 and 91005601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91005613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45502811 + 45502812.

It is an arithmetic number, because the mean of its divisors is an integer number (45502812).

Almost surely, 2^91005623 is an apocalyptic number.

91005623 is a deficient number, since it is larger than the sum of its proper divisors (1).

91005623 is an equidigital number, since it uses as much as digits as its factorization.

91005623 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 91005623 is about 9539.6867348986. The cubic root of 91005623 is about 449.8034087780.

The spelling of 91005623 in words is "ninety-one million, five thousand, six hundred twenty-three".