21405532525 has 48 divisors (see below), whose sum is σ = 30194317440. Its totient is φ = 14922835200.

The previous prime is 21405532523. The next prime is 21405532549. The reversal of 21405532525 is 52523550412.

It is not a de Polignac number, because 21405532525 - 2¹ = 21405532523 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21405532523) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1803360 + ... + 1815190.

It is an arithmetic number, because the mean of its divisors is an integer number (629048280).

Almost surely, 2^21405532525 is an apocalyptic number.

21405532525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21405532525 is a deficient number, since it is larger than the sum of its proper divisors (8788784915).

21405532525 is a wasteful number, since it uses less digits than its factorization.

21405532525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12166 (or 12161 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 34.

The spelling of 21405532525 in words is "twenty-one billion, four hundred five million, five hundred thirty-two thousand, five hundred twenty-five".