11657840 has 20 divisors (see below), whose sum is σ = 27104664. Its totient is φ = 4663104.

The previous prime is 11657839. The next prime is 11657851. The reversal of 11657840 is 4875611.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 11657797 and 11657806.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 72782 + ... + 72941.

Almost surely, 2^11657840 is an apocalyptic number.

11657840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11657840 is an abundant number, since it is smaller than the sum of its proper divisors (15446824).

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

11657840 is a wasteful number, since it uses less digits than its factorization.

11657840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145736 (or 145730 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 11657840 is about 3414.3579191409. The cubic root of 11657840 is about 226.7458585267.

The spelling of 11657840 in words is "eleven million, six hundred fifty-seven thousand, eight hundred forty".