1648778920 has 64 divisors (see below), whose sum is σ = 3965552640. Its totient is φ = 615436800.

The previous prime is 1648778917. The next prime is 1648778939. The reversal of 1648778920 is 298778461.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15865 + ... + 59575.

It is an arithmetic number, because the mean of its divisors is an integer number (61961760).

Almost surely, 2^1648778920 is an apocalyptic number.

1648778920 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 1648778920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1982776320).

1648778920 is an abundant number, since it is smaller than the sum of its proper divisors (2316773720).

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

1648778920 is a wasteful number, since it uses less digits than its factorization.

1648778920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43786 (or 43782 counting only the distinct ones).

The product of its (nonzero) digits is 1354752, while the sum is 52.

The square root of 1648778920 is about 40605.1587855533. The cubic root of 1648778920 is about 1181.3741818813.

The spelling of 1648778920 in words is "one billion, six hundred forty-eight million, seven hundred seventy-eight thousand, nine hundred twenty".