91794781 has 24 divisors (see below), whose sum is σ = 107226504. Its totient is φ = 78074880.

The previous prime is 91794779. The next prime is 91794797. The reversal of 91794781 is 18749719.

It can be written as a sum of positive squares in 12 ways, for example, as 6528025 + 85266756 = 2555^2 + 9234^2 .

It is not a de Polignac number, because 91794781 - 2¹ = 91794779 is a prime.

It is a super-2 number, since 2×91794781² = 16852563637675922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91794481) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 198891 + ... + 199351.

It is an arithmetic number, because the mean of its divisors is an integer number (4467771).

Almost surely, 2^91794781 is an apocalyptic number.

It is an amenable number.

91794781 is a deficient number, since it is larger than the sum of its proper divisors (15431723).

91794781 is a wasteful number, since it uses less digits than its factorization.

91794781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561 (or 544 counting only the distinct ones).

The product of its digits is 127008, while the sum is 46.

The square root of 91794781 is about 9580.9592943504. The cubic root of 91794781 is about 451.0998299172.

The spelling of 91794781 in words is "ninety-one million, seven hundred ninety-four thousand, seven hundred eighty-one".