28729503520081 has 27 divisors (see below), whose sum is σ = 36189172698993. Its totient is φ = 22730649832800.

The previous prime is 28729503520073. The next prime is 28729503520099. The reversal of 28729503520081 is 18002530592782.

The square root of 28729503520081 is 5359991.

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

It can be written as a sum of positive squares in 4 ways, for example, as 18961278347025 + 9768225173056 = 4354455^2 + 3125416^2 .

It is not a de Polignac number, because 28729503520081 - 2³ = 28729503520073 is a prime.

It is a super-2 number, since 2×28729503520081² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28729503520051) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 487729731 + ... + 487788631.

Almost surely, 2^{28729503520081} is an apocalyptic number.

28729503520081 is the 5359991-st square number.

28729503520081 is the 2679996-th centered octagonal number.

It is an amenable number.

28729503520081 is a deficient number, since it is larger than the sum of its proper divisors (7459669178912).

28729503520081 is an frugal number, since it uses more digits than its factorization.

28729503520081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117842 (or 58921 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 52.

The spelling of 28729503520081 in words is "twenty-eight trillion, seven hundred twenty-nine billion, five hundred three million, five hundred twenty thousand, eighty-one".