2291640 has 96 divisors (see below), whose sum is σ = 7510320. Its totient is φ = 559104.

The previous prime is 2291629. The next prime is 2291657. The reversal of 2291640 is 461922.

It is a super-2 number, since 2×2291640² = 10503227779200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 2291640.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 20224 + ... + 20336.

2^2291640 is an apocalyptic number.

2291640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2291640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3755160).

2291640 is an abundant number, since it is smaller than the sum of its proper divisors (5218680).

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

2291640 is a wasteful number, since it uses less digits than its factorization.

2291640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 2291640 is about 1513.8163693130. The cubic root of 2291640 is about 131.8404868392.

The spelling of 2291640 in words is "two million, two hundred ninety-one thousand, six hundred forty".