1641680864 has 48 divisors (see below), whose sum is σ = 3427174800. Its totient is φ = 771922944.

The previous prime is 1641680863. The next prime is 1641680869. The reversal of 1641680864 is 4680861461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1641680863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73442 + ... + 93150.

It is an arithmetic number, because the mean of its divisors is an integer number (71399475).

Almost surely, 2^1641680864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1641680864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1713587400).

1641680864 is an abundant number, since it is smaller than the sum of its proper divisors (1785493936).

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

1641680864 is a wasteful number, since it uses less digits than its factorization.

1641680864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19875 (or 19867 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 44.

The square root of 1641680864 is about 40517.6611368425. The cubic root of 1641680864 is about 1179.6764563499.

The spelling of 1641680864 in words is "one billion, six hundred forty-one million, six hundred eighty thousand, eight hundred sixty-four".