221580142729 has 9 divisors (see below), whose sum is σ = 243560724519. Its totient is φ = 201431786160.

The previous prime is 221580142661. The next prime is 221580142787. The reversal of 221580142729 is 927241085122.

The square root of 221580142729 is 470723.

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., 115793881225 + 105786261504 = 340285^2 + 325248^2 .

It is not a de Polignac number, because 221580142729 - 2¹⁷ = 221580011657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221500142729) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5156557 + ... + 5199349.

Almost surely, 2^221580142729 is an apocalyptic number.

221580142729 is the 470723-rd square number.

221580142729 is the 235362-nd centered octagonal number.

It is an amenable number.

221580142729 is a deficient number, since it is larger than the sum of its proper divisors (21980581790).

221580142729 is an frugal number, since it uses more digits than its factorization.

221580142729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85608 (or 42804 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 43.

The spelling of 221580142729 in words is "two hundred twenty-one billion, five hundred eighty million, one hundred forty-two thousand, seven hundred twenty-nine".