2644402391 has 8 divisors (see below), whose sum is σ = 2761382400. Its totient is φ = 2527589592.

The previous prime is 2644402373. The next prime is 2644402421. The reversal of 2644402391 is 1932044462.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2644402391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2644402591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8915 + ... + 73268.

It is an arithmetic number, because the mean of its divisors is an integer number (345172800).

Almost surely, 2^2644402391 is an apocalyptic number.

2644402391 is a deficient number, since it is larger than the sum of its proper divisors (116980009).

2644402391 is a wasteful number, since it uses less digits than its factorization.

2644402391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83605.

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 2644402391 is about 51423.7531788569. The cubic root of 2644402391 is about 1382.8524614107.

The spelling of 2644402391 in words is "two billion, six hundred forty-four million, four hundred two thousand, three hundred ninety-one".