91019623 has 2 divisors, whose sum is σ = 91019624. Its totient is φ = 91019622.

The previous prime is 91019587. The next prime is 91019641. The reversal of 91019623 is 32691019.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91019623 - 2⁹ = 91019111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91019653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45509811 + 45509812.

It is an arithmetic number, because the mean of its divisors is an integer number (45509812).

Almost surely, 2^91019623 is an apocalyptic number.

91019623 is a deficient number, since it is larger than the sum of its proper divisors (1).

91019623 is an equidigital number, since it uses as much as digits as its factorization.

91019623 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 91019623 is about 9540.4204833959. The cubic root of 91019623 is about 449.8264730116.

The spelling of 91019623 in words is "ninety-one million, nineteen thousand, six hundred twenty-three".