91697440 has 24 divisors (see below), whose sum is σ = 216635580. Its totient is φ = 36678912.

The previous prime is 91697413. The next prime is 91697447. The reversal of 91697440 is 4479619.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 88585744 + 3111696 = 9412^2 + 1764^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 91697393 and 91697402.

It is not an unprimeable number, because it can be changed into a prime (91697447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 286395 + ... + 286714.

Almost surely, 2^91697440 is an apocalyptic number.

It is an amenable number.

91697440 is an abundant number, since it is smaller than the sum of its proper divisors (124938140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91697440 is a wasteful number, since it uses less digits than its factorization.

91697440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 573124 (or 573116 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 91697440 is about 9575.8780276275. The cubic root of 91697440 is about 450.9403217970.

The spelling of 91697440 in words is "ninety-one million, six hundred ninety-seven thousand, four hundred forty".