2721043644 has 72 divisors (see below), whose sum is σ = 6989203200. Its totient is φ = 823326240.

The previous prime is 2721043643. The next prime is 2721043651. The reversal of 2721043644 is 4463401272.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2721043643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1600707 + ... + 1602405.

Almost surely, 2^2721043644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2721043644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3494601600).

2721043644 is an abundant number, since it is smaller than the sum of its proper divisors (4268159556).

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

2721043644 is a wasteful number, since it uses less digits than its factorization.

2721043644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2831 (or 2818 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 33.

The square root of 2721043644 is about 52163.6237621582. The cubic root of 2721043644 is about 1396.0849195611.

The spelling of 2721043644 in words is "two billion, seven hundred twenty-one million, forty-three thousand, six hundred forty-four".