91444989 has 16 divisors (see below), whose sum is σ = 129435840. Its totient is φ = 57227520.

The previous prime is 91444979. The next prime is 91444993. The reversal of 91444989 is 98944419.

It is a happy number.

It is not a de Polignac number, because 91444989 - 2⁴ = 91444973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91444909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19342 + ... + 23600.

It is an arithmetic number, because the mean of its divisors is an integer number (8089740).

Almost surely, 2^91444989 is an apocalyptic number.

It is an amenable number.

91444989 is a deficient number, since it is larger than the sum of its proper divisors (37990851).

91444989 is a wasteful number, since it uses less digits than its factorization.

91444989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4700.

The product of its digits is 373248, while the sum is 48.

The square root of 91444989 is about 9562.6873314984. The cubic root of 91444989 is about 450.5261155188.

The spelling of 91444989 in words is "ninety-one million, four hundred forty-four thousand, nine hundred eighty-nine".