1621886976 has 144 divisors (see below), whose sum is σ = 4859290800. Its totient is φ = 540463104.

The previous prime is 1621886963. The next prime is 1621887017. The reversal of 1621886976 is 6796881261.

1621886976 is a `hidden beast` number, since 1 + 621 + 8 + 8 + 6 + 9 + 7 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 496035 + ... + 499293.

It is an arithmetic number, because the mean of its divisors is an integer number (33745075).

Almost surely, 2^1621886976 is an apocalyptic number.

1621886976 is a gapful number since it is divisible by the number (16) 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 1621886976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2429645400).

1621886976 is an abundant number, since it is smaller than the sum of its proper divisors (3237403824).

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

1621886976 is an frugal number, since it uses more digits than its factorization.

1621886976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3296 (or 3264 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The square root of 1621886976 is about 40272.6579207283. The cubic root of 1621886976 is about 1174.9161191969.

The spelling of 1621886976 in words is "one billion, six hundred twenty-one million, eight hundred eighty-six thousand, nine hundred seventy-six".