91225640 has 32 divisors (see below), whose sum is σ = 223918560. Its totient is φ = 33172800.

The previous prime is 91225633. The next prime is 91225643. The reversal of 91225640 is 4652219.

It is a happy number.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (91225643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103226 + ... + 104105.

It is an arithmetic number, because the mean of its divisors is an integer number (6997455).

Almost surely, 2^91225640 is an apocalyptic number.

It is an amenable number.

91225640 is an abundant number, since it is smaller than the sum of its proper divisors (132692920).

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

91225640 is a wasteful number, since it uses less digits than its factorization.

91225640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207353 (or 207349 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 91225640 is about 9551.2114414874. The cubic root of 91225640 is about 450.1656016020.

Adding to 91225640 its reverse (4652219), we get a palindrome (95877859).

The spelling of 91225640 in words is "ninety-one million, two hundred twenty-five thousand, six hundred forty".