1644391796 has 12 divisors (see below), whose sum is σ = 2878354080. Its totient is φ = 822004920.

The previous prime is 1644391789. The next prime is 1644391799. The reversal of 1644391796 is 6971934461.

It is a happy number.

It is a super-3 number, since 3×1644391796³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644391799) 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, 27410 + ... + 63561.

It is an arithmetic number, because the mean of its divisors is an integer number (239862840).

Almost surely, 2^1644391796 is an apocalyptic number.

It is an amenable number.

1644391796 is a deficient number, since it is larger than the sum of its proper divisors (1233962284).

1644391796 is a wasteful number, since it uses less digits than its factorization.

1644391796 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95494 (or 95492 counting only the distinct ones).

The product of its digits is 979776, while the sum is 50.

The square root of 1644391796 is about 40551.1010454710. The cubic root of 1644391796 is about 1180.3254383424.

The spelling of 1644391796 in words is "one billion, six hundred forty-four million, three hundred ninety-one thousand, seven hundred ninety-six".