91144643 has 2 divisors, whose sum is σ = 91144644. Its totient is φ = 91144642.

The previous prime is 91144583. The next prime is 91144687. The reversal of 91144643 is 34644119.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (34644119) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91144643 - 2¹² = 91140547 is a prime.

It is not a weakly prime, because it can be changed into another prime (91144243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45572321 + 45572322.

It is an arithmetic number, because the mean of its divisors is an integer number (45572322).

Almost surely, 2^91144643 is an apocalyptic number.

91144643 is a deficient number, since it is larger than the sum of its proper divisors (1).

91144643 is an equidigital number, since it uses as much as digits as its factorization.

91144643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 32.

The square root of 91144643 is about 9546.9703571342. The cubic root of 91144643 is about 450.0323318333.

It can be divided in two parts, 911 and 44643, that added together give a palindrome (45554).

The spelling of 91144643 in words is "ninety-one million, one hundred forty-four thousand, six hundred forty-three".