21521344201 has 16 divisors (see below), whose sum is σ = 24717456000. Its totient is φ = 18355736448.

The previous prime is 21521344199. The next prime is 21521344253. The reversal of 21521344201 is 10244312512.

It is not a de Polignac number, because 21521344201 - 2¹ = 21521344199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21521342201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4218150 + ... + 4223248.

It is an arithmetic number, because the mean of its divisors is an integer number (1544841000).

Almost surely, 2^21521344201 is an apocalyptic number.

It is an amenable number.

21521344201 is a deficient number, since it is larger than the sum of its proper divisors (3196111799).

21521344201 is a wasteful number, since it uses less digits than its factorization.

21521344201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7968.

The product of its (nonzero) digits is 1920, while the sum is 25.

Adding to 21521344201 its reverse (10244312512), we get a palindrome (31765656713).

The spelling of 21521344201 in words is "twenty-one billion, five hundred twenty-one million, three hundred forty-four thousand, two hundred one".