1644721342 has 8 divisors (see below), whose sum is σ = 2691362232. Its totient is φ = 747600600.

The previous prime is 1644721327. The next prime is 1644721349. The reversal of 1644721342 is 2431274461.

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

It is a junction number, because it is equal to n+sod(n) for n = 1644721298 and 1644721307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644721349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37380009 + ... + 37380052.

It is an arithmetic number, because the mean of its divisors is an integer number (336420279).

Almost surely, 2^1644721342 is an apocalyptic number.

1644721342 is a deficient number, since it is larger than the sum of its proper divisors (1046640890).

1644721342 is a wasteful number, since it uses less digits than its factorization.

1644721342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74760074.

The product of its digits is 32256, while the sum is 34.

The square root of 1644721342 is about 40555.1641841085. The cubic root of 1644721342 is about 1180.4042811799.

The spelling of 1644721342 in words is "one billion, six hundred forty-four million, seven hundred twenty-one thousand, three hundred forty-two".