3639720 has 96 divisors (see below), whose sum is σ = 12722400. Its totient is φ = 830592.

The previous prime is 3639719. The next prime is 3639733. The reversal of 3639720 is 279363.

It is a happy number.

3639720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an Ulam 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 23 ways as a sum of consecutive naturals, for example, 5571 + ... + 6189.

It is an arithmetic number, because the mean of its divisors is an integer number (132525).

Almost surely, 2^3639720 is an apocalyptic number.

3639720 is a gapful number since it is divisible by the number (30) 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 3639720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6361200).

3639720 is an abundant number, since it is smaller than the sum of its proper divisors (9082680).

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

3639720 is a wasteful number, since it uses less digits than its factorization.

3639720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 647 (or 636 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 30.

The square root of 3639720 is about 1907.8050214841. The cubic root of 3639720 is about 153.8234892253.

The spelling of 3639720 in words is "three million, six hundred thirty-nine thousand, seven hundred twenty".