21020330455525 has 24 divisors (see below), whose sum is σ = 27041271201000. Its totient is φ = 16189870368000.

The previous prime is 21020330455483. The next prime is 21020330455529. The reversal of 21020330455525 is 52555403302012.

It can be written as a sum of positive squares in 12 ways, for example, as 6556129524036 + 14464200931489 = 2560494^2 + 3803183^2 .

It is not a de Polignac number, because 21020330455525 - 2³³ = 21011740520933 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020330455529) 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 23 ways as a sum of consecutive naturals, for example, 41285026 + ... + 41791075.

It is an arithmetic number, because the mean of its divisors is an integer number (1126719633375).

Almost surely, 2^{21020330455525} is an apocalyptic number.

21020330455525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21020330455525 is a deficient number, since it is larger than the sum of its proper divisors (6020940745475).

21020330455525 is a wasteful number, since it uses less digits than its factorization.

21020330455525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83076489 (or 83076484 counting only the distinct ones).

The product of its (nonzero) digits is 180000, while the sum is 37.

Adding to 21020330455525 its reverse (52555403302012), we get a palindrome (73575733757537).

The spelling of 21020330455525 in words is "twenty-one trillion, twenty billion, three hundred thirty million, four hundred fifty-five thousand, five hundred twenty-five".