21221201504 has 24 divisors (see below), whose sum is σ = 41783060088. Its totient is φ = 10609630720.

The previous prime is 21221201503. The next prime is 21221201531. The reversal of 21221201504 is 40510212212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221201503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 435119 + ... + 481425.

It is an arithmetic number, because the mean of its divisors is an integer number (1740960837).

Almost surely, 2^21221201504 is an apocalyptic number.

It is an amenable number.

21221201504 is a deficient number, since it is larger than the sum of its proper divisors (20561858584).

21221201504 is a wasteful number, since it uses less digits than its factorization.

21221201504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60638 (or 60630 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

Adding to 21221201504 its reverse (40510212212), we get a palindrome (61731413716).

The spelling of 21221201504 in words is "twenty-one billion, two hundred twenty-one million, two hundred one thousand, five hundred four".