1978130664 has 96 divisors (see below), whose sum is σ = 5429099520. Its totient is φ = 650619648.

The previous prime is 1978130657. The next prime is 1978130681. The reversal of 1978130664 is 4660318791.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2075212 + ... + 2076164.

It is an arithmetic number, because the mean of its divisors is an integer number (56553120).

Almost surely, 2^1978130664 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 1978130664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2714549760).

1978130664 is an abundant number, since it is smaller than the sum of its proper divisors (3450968856).

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

1978130664 is a wasteful number, since it uses less digits than its factorization.

1978130664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1319 (or 1312 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 1978130664 is about 44476.1808612205. The cubic root of 1978130664 is about 1255.3119363437.

The spelling of 1978130664 in words is "one billion, nine hundred seventy-eight million, one hundred thirty thousand, six hundred sixty-four".