21215730801 has 4 divisors (see below), whose sum is σ = 28287641072. Its totient is φ = 14143820532.

The previous prime is 21215730797. The next prime is 21215730853. The reversal of 21215730801 is 10803751212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21215730801 - 2² = 21215730797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21215730101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3535955131 + ... + 3535955136.

It is an arithmetic number, because the mean of its divisors is an integer number (7071910268).

Almost surely, 2^21215730801 is an apocalyptic number.

It is an amenable number.

21215730801 is a deficient number, since it is larger than the sum of its proper divisors (7071910271).

21215730801 is an equidigital number, since it uses as much as digits as its factorization.

21215730801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7071910270.

The product of its (nonzero) digits is 3360, while the sum is 30.

The spelling of 21215730801 in words is "twenty-one billion, two hundred fifteen million, seven hundred thirty thousand, eight hundred one".