21143301721 has 8 divisors (see below), whose sum is σ = 22041439488. Its totient is φ = 20258670000.

The previous prime is 21143301709. The next prime is 21143301731. The reversal of 21143301721 is 12710334112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21143301721 - 2¹³ = 21143293529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21143301731) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 3373315 + ... + 3379576.

It is an arithmetic number, because the mean of its divisors is an integer number (2755179936).

Almost surely, 2^21143301721 is an apocalyptic number.

It is an amenable number.

21143301721 is a deficient number, since it is larger than the sum of its proper divisors (898137767).

21143301721 is a wasteful number, since it uses less digits than its factorization.

21143301721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6753023.

The product of its (nonzero) digits is 1008, while the sum is 25.

Adding to 21143301721 its reverse (12710334112), we get a palindrome (33853635833).

The spelling of 21143301721 in words is "twenty-one billion, one hundred forty-three million, three hundred one thousand, seven hundred twenty-one".