21220400224 has 24 divisors (see below), whose sum is σ = 41783113008. Its totient is φ = 10608816000.

The previous prime is 21220400213. The next prime is 21220400237. The reversal of 21220400224 is 42200402212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233029 + ... + 311035.

It is an arithmetic number, because the mean of its divisors is an integer number (1740963042).

Almost surely, 2^21220400224 is an apocalyptic number.

It is an amenable number.

21220400224 is a deficient number, since it is larger than the sum of its proper divisors (20562712784).

21220400224 is an equidigital number, since it uses as much as digits as its factorization.

21220400224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86518 (or 86510 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 19.

Adding to 21220400224 its reverse (42200402212), we get a palindrome (63420802436).

The spelling of 21220400224 in words is "twenty-one billion, two hundred twenty million, four hundred thousand, two hundred twenty-four".