28015729641 has 9 divisors (see below), whose sum is σ = 40467890359. Its totient is φ = 18676818336.

The previous prime is 28015729579. The next prime is 28015729657. The reversal of 28015729641 is 14692751082.

The square root of 28015729641 is 167379.

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., 1996749225 + 26018980416 = 44685^2 + 161304^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 28015729641 - 2⁹ = 28015729129 is a prime.

It is a super-2 number, since 2×28015729641² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28015729661) 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, 474241 + ... + 530033.

Almost surely, 2^28015729641 is an apocalyptic number.

28015729641 is the 167379-th square number.

28015729641 is the 83690-th centered octagonal number.

It is an amenable number.

28015729641 is a deficient number, since it is larger than the sum of its proper divisors (12452160718).

28015729641 is an frugal number, since it uses more digits than its factorization.

28015729641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111592 (or 55796 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 28015729641 in words is "twenty-eight billion, fifteen million, seven hundred twenty-nine thousand, six hundred forty-one".