13820640 has 48 divisors (see below), whose sum is σ = 43536528. Its totient is φ = 3685376.

The previous prime is 13820633. The next prime is 13820671. The reversal of 13820640 is 4602831.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

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 13820640.

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 7 ways as a sum of consecutive naturals, for example, 13917 + ... + 14876.

It is an arithmetic number, because the mean of its divisors is an integer number (907011).

Almost surely, 2^13820640 is an apocalyptic number.

13820640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13820640 is an abundant number, since it is smaller than the sum of its proper divisors (29715888).

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

13820640 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 9 representation: 13820640 = (28004316)₉.

13820640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28811 (or 28803 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 13820640 is about 3717.6121368427. The cubic root of 13820640 is about 239.9805539800.

The spelling of 13820640 in words is "thirteen million, eight hundred twenty thousand, six hundred forty".