21221454524 has 12 divisors (see below), whose sum is σ = 37139207448. Its totient is φ = 10610252400.

The previous prime is 21221454437. The next prime is 21221454593. The reversal of 21221454524 is 42545412212.

It is a super-2 number, since 2×21221454524² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6347 + ... + 206114.

It is an arithmetic number, because the mean of its divisors is an integer number (3094933954).

Almost surely, 2^21221454524 is an apocalyptic number.

It is an amenable number.

21221454524 is a deficient number, since it is larger than the sum of its proper divisors (15917752924).

21221454524 is a wasteful number, since it uses less digits than its factorization.

21221454524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237436 (or 237434 counting only the distinct ones).

The product of its digits is 25600, while the sum is 32.

Adding to 21221454524 its reverse (42545412212), we get a palindrome (63766866736).

The spelling of 21221454524 in words is "twenty-one billion, two hundred twenty-one million, four hundred fifty-four thousand, five hundred twenty-four".