21301221013 has 4 divisors (see below), whose sum is σ = 21508029088. Its totient is φ = 21094412940.

The previous prime is 21301221001. The next prime is 21301221023. The reversal of 21301221013 is 31012210312.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21301221013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21301221023) 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, 103403883 + ... + 103404088.

It is an arithmetic number, because the mean of its divisors is an integer number (5377007272).

Almost surely, 2^21301221013 is an apocalyptic number.

It is an amenable number.

21301221013 is a deficient number, since it is larger than the sum of its proper divisors (206808075).

21301221013 is a wasteful number, since it uses less digits than its factorization.

21301221013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206808074.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21301221013 its reverse (31012210312), we get a palindrome (52313431325).

The spelling of 21301221013 in words is "twenty-one billion, three hundred one million, two hundred twenty-one thousand, thirteen".