221609328516 has 45 divisors (see below), whose sum is σ = 579352711861. Its totient is φ = 73866951648.

The previous prime is 221609328487. The next prime is 221609328533. The reversal of 221609328516 is 615823906122.

The square root of 221609328516 is 470754.

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

221609328516 is a `hidden beast` number, since 2 + 2 + 1 + 609 + 3 + 28 + 5 + 16 = 666.

It can be written as a sum of positive squares in only one way, i.e., 27572602500 + 194036726016 = 166050^2 + 440496^2 .

It is a super-2 number, since 2×221609328516² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 8460496 + ... + 8486648.

Almost surely, 2^221609328516 is an apocalyptic number.

221609328516 is the 470754-th square number.

It is an amenable number.

221609328516 is an abundant number, since it is smaller than the sum of its proper divisors (357743383345).

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

221609328516 is an frugal number, since it uses more digits than its factorization.

221609328516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52322 (or 26158 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 221609328516 in words is "two hundred twenty-one billion, six hundred nine million, three hundred twenty-eight thousand, five hundred sixteen".