21530423504025 has 36 divisors (see below), whose sum is σ = 38625680499120. Its totient is φ = 11464341746400.

The previous prime is 21530423503991. The next prime is 21530423504077. The reversal of 21530423504025 is 52040532403512.

21530423504025 is a `hidden beast` number, since 2 + 15 + 3 + 0 + 4 + 235 + 0 + 402 + 5 = 666.

It is not a de Polignac number, because 21530423504025 - 2⁸ = 21530423503769 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 77155371 + ... + 77433920.

It is an arithmetic number, because the mean of its divisors is an integer number (1072935569420).

Almost surely, 2^{21530423504025} is an apocalyptic number.

21530423504025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21530423504025 is a deficient number, since it is larger than the sum of its proper divisors (17095256995095).

21530423504025 is a wasteful number, since it uses less digits than its factorization.

21530423504025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154589926 (or 154589918 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 36.

Adding to 21530423504025 its reverse (52040532403512), we get a palindrome (73570955907537).

The spelling of 21530423504025 in words is "twenty-one trillion, five hundred thirty billion, four hundred twenty-three million, five hundred four thousand, twenty-five".