21530400450525 has 18 divisors (see below), whose sum is σ = 38563339474010. Its totient is φ = 11482880240160.

The previous prime is 21530400450511. The next prime is 21530400450527. The reversal of 21530400450525 is 52505400403512.

21530400450525 is a `hidden beast` number, since 2 + 1 + 53 + 0 + 40 + 0 + 45 + 0 + 525 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 298699413156 + 21231701037369 = 546534^2 + 4607787^2 .

It is not a de Polignac number, because 21530400450525 - 2⁴ = 21530400450509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21530400450525.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530400450527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 47845334110 + ... + 47845334559.

Almost surely, 2^{21530400450525} is an apocalyptic number.

21530400450525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21530400450525 is a deficient number, since it is larger than the sum of its proper divisors (17032939023485).

21530400450525 is a wasteful number, since it uses less digits than its factorization.

21530400450525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95690668685 (or 95690668677 counting only the distinct ones).

The product of its (nonzero) digits is 120000, while the sum is 36.

The spelling of 21530400450525 in words is "twenty-one trillion, five hundred thirty billion, four hundred million, four hundred fifty thousand, five hundred twenty-five".