1621864648 has 8 divisors (see below), whose sum is σ = 3040996230. Its totient is φ = 810932320.

The previous prime is 1621864627. The next prime is 1621864661. The reversal of 1621864648 is 8464681261.

It can be written as a sum of positive squares in only one way, i.e., 1349680644 + 272184004 = 36738^2 + 16498^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 1621864598 and 1621864607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101366533 + ... + 101366548.

Almost surely, 2^1621864648 is an apocalyptic number.

It is an amenable number.

1621864648 is a deficient number, since it is larger than the sum of its proper divisors (1419131582).

1621864648 is a wasteful number, since it uses less digits than its factorization.

1621864648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202733087 (or 202733083 counting only the distinct ones).

The product of its digits is 442368, while the sum is 46.

The square root of 1621864648 is about 40272.3807093646. The cubic root of 1621864648 is about 1174.9107276072.

The spelling of 1621864648 in words is "one billion, six hundred twenty-one million, eight hundred sixty-four thousand, six hundred forty-eight".