1659931644 has 72 divisors (see below), whose sum is σ = 4511157840. Its totient is φ = 473673984.

The previous prime is 1659931631. The next prime is 1659931657. The reversal of 1659931644 is 4461399561.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1659931631) and next prime (1659931657).

It is a junction number, because it is equal to n+sod(n) for n = 1659931593 and 1659931602.

It is a congruent number.

It is an unprimeable number.

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, 721504 + ... + 723800.

It is an arithmetic number, because the mean of its divisors is an integer number (62654970).

Almost surely, 2^1659931644 is an apocalyptic number.

1659931644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1659931644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2255578920).

1659931644 is an abundant number, since it is smaller than the sum of its proper divisors (2851226196).

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

1659931644 is a wasteful number, since it uses less digits than its factorization.

1659931644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3547 (or 3538 counting only the distinct ones).

The product of its digits is 699840, while the sum is 48.

The square root of 1659931644 is about 40742.2587002734. The cubic root of 1659931644 is about 1184.0318949513.

The spelling of 1659931644 in words is "one billion, six hundred fifty-nine million, nine hundred thirty-one thousand, six hundred forty-four".