21221524546436 has 6 divisors (see below), whose sum is σ = 37137667956270. Its totient is φ = 10610762273216.

The previous prime is 21221524546433. The next prime is 21221524546441. The reversal of 21221524546436 is 63464542512212.

It can be written as a sum of positive squares in only one way, i.e., 19638724033600 + 1582800512836 = 4431560^2 + 1258094^2 .

It is not an unprimeable number, because it can be changed into a prime (21221524546433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2652690568301 + ... + 2652690568308.

It is an arithmetic number, because the mean of its divisors is an integer number (6189611326045).

Almost surely, 2^{21221524546436} is an apocalyptic number.

It is an amenable number.

21221524546436 is a deficient number, since it is larger than the sum of its proper divisors (15916143409834).

21221524546436 is a wasteful number, since it uses less digits than its factorization.

21221524546436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5305381136613 (or 5305381136611 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 47.

The spelling of 21221524546436 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred twenty-four million, five hundred forty-six thousand, four hundred thirty-six".