1681759444 has 6 divisors (see below), whose sum is σ = 2943079034. Its totient is φ = 840879720.

The previous prime is 1681759441. The next prime is 1681759481. The reversal of 1681759444 is 4449571861.

It can be written as a sum of positive squares in only one way, i.e., 954810000 + 726949444 = 30900^2 + 26962^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681759441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210219927 + ... + 210219934.

Almost surely, 2^1681759444 is an apocalyptic number.

It is an amenable number.

1681759444 is a deficient number, since it is larger than the sum of its proper divisors (1261319590).

1681759444 is a wasteful number, since it uses less digits than its factorization.

1681759444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420439865 (or 420439863 counting only the distinct ones).

The product of its digits is 967680, while the sum is 49.

The square root of 1681759444 is about 41009.2604663873. The cubic root of 1681759444 is about 1189.1992456754.

The spelling of 1681759444 in words is "one billion, six hundred eighty-one million, seven hundred fifty-nine thousand, four hundred forty-four".