91387920 has 160 divisors (see below), whose sum is σ = 323229312. Its totient is φ = 21159936.

The previous prime is 91387867. The next prime is 91387921. The reversal of 91387920 is 2978319.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (91387921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52179 + ... + 53901.

Almost surely, 2^91387920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91387920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161614656).

91387920 is an abundant number, since it is smaller than the sum of its proper divisors (231841392).

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

91387920 is a wasteful number, since it uses less digits than its factorization.

91387920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1769 (or 1763 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 91387920 is about 9559.7029242545. The cubic root of 91387920 is about 450.4323745510.

The spelling of 91387920 in words is "ninety-one million, three hundred eighty-seven thousand, nine hundred twenty".