21221524540545 has 64 divisors (see below), whose sum is σ = 39634539134976. Its totient is φ = 9493941795840.

The previous prime is 21221524540543. The next prime is 21221524540553. The reversal of 21221524540545 is 54504542512212.

It is not a de Polignac number, because 21221524540545 - 2¹ = 21221524540543 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21221524540497 and 21221524540506.

It is not an unprimeable number, because it can be changed into a prime (21221524540543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 52261737 + ... + 52666233.

It is an arithmetic number, because the mean of its divisors is an integer number (619289673984).

Almost surely, 2^{21221524540545} is an apocalyptic number.

It is an amenable number.

21221524540545 is a deficient number, since it is larger than the sum of its proper divisors (18413014594431).

21221524540545 is a wasteful number, since it uses less digits than its factorization.

21221524540545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415190.

The product of its (nonzero) digits is 640000, while the sum is 42.

The spelling of 21221524540545 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred twenty-four million, five hundred forty thousand, five hundred forty-five".