91644981 has 8 divisors (see below), whose sum is σ = 122522400. Its totient is φ = 60932112.

The previous prime is 91644953. The next prime is 91644989. The reversal of 91644981 is 18944619.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91644981 - 2¹⁷ = 91513909 is a prime.

It is a super-2 number, since 2×91644981² = 16797605084980722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91644989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39831 + ... + 42068.

It is an arithmetic number, because the mean of its divisors is an integer number (15315300).

Almost surely, 2^91644981 is an apocalyptic number.

It is an amenable number.

91644981 is a deficient number, since it is larger than the sum of its proper divisors (30877419).

91644981 is a wasteful number, since it uses less digits than its factorization.

91644981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82275.

The product of its digits is 62208, while the sum is 42.

The square root of 91644981 is about 9573.1385135701. The cubic root of 91644981 is about 450.8543128861.

The spelling of 91644981 in words is "ninety-one million, six hundred forty-four thousand, nine hundred eighty-one".