21549652804 has 27 divisors (see below), whose sum is σ = 39072581821. Its totient is φ = 10399170320.

The previous prime is 21549652783. The next prime is 21549652811. The reversal of 21549652804 is 40825694512.

The square root of 21549652804 is 146798.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 11300115204 + 10249537600 = 106302^2 + 101240^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 8513019 + ... + 8515549.

Almost surely, 2^21549652804 is an apocalyptic number.

21549652804 is the 146798-th square number.

It is an amenable number.

21549652804 is a deficient number, since it is larger than the sum of its proper divisors (17522929017).

21549652804 is an frugal number, since it uses more digits than its factorization.

21549652804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5124 (or 2562 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 46.

The spelling of 21549652804 in words is "twenty-one billion, five hundred forty-nine million, six hundred fifty-two thousand, eight hundred four".