13640820 has 48 divisors (see below), whose sum is σ = 38830848. Its totient is φ = 3576960.

The previous prime is 13640813. The next prime is 13640831. The reversal of 13640820 is 2804631.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1797 + ... + 5523.

It is an arithmetic number, because the mean of its divisors is an integer number (808976).

Almost surely, 2^13640820 is an apocalyptic number.

13640820 is a gapful number since it is divisible by the number (10) 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 13640820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19415424).

13640820 is an abundant number, since it is smaller than the sum of its proper divisors (25190028).

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

13640820 is a wasteful number, since it uses less digits than its factorization.

13640820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3800 (or 3798 counting only the distinct ones).

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

The square root of 13640820 is about 3693.3480745795. The cubic root of 13640820 is about 238.9352134989.

The spelling of 13640820 in words is "thirteen million, six hundred forty thousand, eight hundred twenty".