21223217524 has 24 divisors (see below), whose sum is σ = 38845433088. Its totient is φ = 10126665120.

The previous prime is 21223217513. The next prime is 21223217549. The reversal of 21223217524 is 42571232212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 227967 + ... + 307270.

It is an arithmetic number, because the mean of its divisors is an integer number (1618559712).

Almost surely, 2^21223217524 is an apocalyptic number.

It is an amenable number.

21223217524 is a deficient number, since it is larger than the sum of its proper divisors (17622215564).

21223217524 is a wasteful number, since it uses less digits than its factorization.

21223217524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535695 (or 535693 counting only the distinct ones).

The product of its digits is 13440, while the sum is 31.

Adding to 21223217524 its reverse (42571232212), we get a palindrome (63794449736).

The spelling of 21223217524 in words is "twenty-one billion, two hundred twenty-three million, two hundred seventeen thousand, five hundred twenty-four".