2780961664 has 64 divisors (see below), whose sum is σ = 5975837280. Its totient is φ = 1281484800.

The previous prime is 2780961613. The next prime is 2780961683. The reversal of 2780961664 is 4661690872.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1714774 + ... + 1716394.

Almost surely, 2^2780961664 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 2780961664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2987918640).

2780961664 is an abundant number, since it is smaller than the sum of its proper divisors (3194875616).

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

2780961664 is a wasteful number, since it uses less digits than its factorization.

2780961664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2679 (or 2667 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 49.

The square root of 2780961664 is about 52734.8240160143. The cubic root of 2780961664 is about 1406.2579824956.

The spelling of 2780961664 in words is "two billion, seven hundred eighty million, nine hundred sixty-one thousand, six hundred sixty-four".