28405712749401 has 45 divisors (see below), whose sum is σ = 45949412340909. Its totient is φ = 17480054876544.

The previous prime is 28405712749391. The next prime is 28405712749433. The reversal of 28405712749401 is 10494721750482.

It is a happy number.

The square root of 28405712749401 is 5329701.

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

28405712749401 is a `hidden beast` number, since 2 + 8 + 4 + 0 + 571 + 27 + 4 + 9 + 40 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 268841213001 + 28136871536400 = 518499^2 + 5304420^2 .

It is not a de Polignac number, because 28405712749401 - 2¹¹ = 28405712747353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28405712049401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 623552241 + ... + 623597793.

Almost surely, 2^{28405712749401} is an apocalyptic number.

28405712749401 is the 5329701-st square number.

28405712749401 is the 2664851-st centered octagonal number.

It is an amenable number.

28405712749401 is a deficient number, since it is larger than the sum of its proper divisors (17543699591508).

28405712749401 is an frugal number, since it uses more digits than its factorization.

28405712749401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91144 (or 45569 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 54.

The spelling of 28405712749401 in words is "twenty-eight trillion, four hundred five billion, seven hundred twelve million, seven hundred forty-nine thousand, four hundred one".