91653840 has 60 divisors (see below), whose sum is σ = 307806564. Its totient is φ = 24440832.

The previous prime is 91653839. The next prime is 91653841. The reversal of 91653840 is 4835619.

It is an interprime number because it is at equal distance from previous prime (91653839) and next prime (91653841).

It can be written as a sum of positive squares in 2 ways, for example, as 58614336 + 33039504 = 7656^2 + 5748^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 91653795 and 91653804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91653841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62929 + ... + 64368.

Almost surely, 2^91653840 is an apocalyptic number.

91653840 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

91653840 is an abundant number, since it is smaller than the sum of its proper divisors (216152724).

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

91653840 is a wasteful number, since it uses less digits than its factorization.

91653840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127316 (or 127307 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 91653840 is about 9573.6012033090. The cubic root of 91653840 is about 450.8688399215.

It can be divided in two parts, 916 and 53840, that added together give a square (54756 = 234²).

The spelling of 91653840 in words is "ninety-one million, six hundred fifty-three thousand, eight hundred forty".