5521721660 has 48 divisors (see below), whose sum is σ = 14271531456. Its totient is φ = 1747533312.

The previous prime is 5521721599. The next prime is 5521721671. The reversal of 5521721660 is 661271255.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 5521721660.

It is a congruent number.

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, 1515137 + ... + 1518776.

It is an arithmetic number, because the mean of its divisors is an integer number (297323572).

Almost surely, 2^5521721660 is an apocalyptic number.

It is an amenable number.

5521721660 is an abundant number, since it is smaller than the sum of its proper divisors (8749809796).

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

5521721660 is a wasteful number, since it uses less digits than its factorization.

5521721660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3033942 (or 3033940 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 35.

The square root of 5521721660 is about 74308.2879630530. The cubic root of 5521721660 is about 1767.4949038463.

The spelling of 5521721660 in words is "five billion, five hundred twenty-one million, seven hundred twenty-one thousand, six hundred sixty".