91919623 has 2 divisors, whose sum is σ = 91919624. Its totient is φ = 91919622.

The previous prime is 91919603. The next prime is 91919627. The reversal of 91919623 is 32691919.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91919623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91919627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45959811 + 45959812.

It is an arithmetic number, because the mean of its divisors is an integer number (45959812).

Almost surely, 2^91919623 is an apocalyptic number.

91919623 is a deficient number, since it is larger than the sum of its proper divisors (1).

91919623 is an equidigital number, since it uses as much as digits as its factorization.

91919623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26244, while the sum is 40.

The square root of 91919623 is about 9587.4721903117. The cubic root of 91919623 is about 451.3042376675.

The spelling of 91919623 in words is "ninety-one million, nine hundred nineteen thousand, six hundred twenty-three".