1644516340 has 96 divisors (see below), whose sum is σ = 3670531200. Its totient is φ = 617971200.

The previous prime is 1644516337. The next prime is 1644516409. The reversal of 1644516340 is 436154461.

It is a junction number, because it is equal to n+sod(n) for n = 1644516296 and 1644516305.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3924651 + ... + 3925069.

It is an arithmetic number, because the mean of its divisors is an integer number (38234700).

Almost surely, 2^1644516340 is an apocalyptic number.

1644516340 is a gapful number since it is divisible by the number (10) 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 1644516340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1835265600).

1644516340 is an abundant number, since it is smaller than the sum of its proper divisors (2026014860).

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

1644516340 is a wasteful number, since it uses less digits than its factorization.

1644516340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 625 (or 623 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 1644516340 is about 40552.6366590386. The cubic root of 1644516340 is about 1180.3552363383.

The spelling of 1644516340 in words is "one billion, six hundred forty-four million, five hundred sixteen thousand, three hundred forty".