21521444611 has 8 divisors (see below), whose sum is σ = 21751241904. Its totient is φ = 21291809280.

The previous prime is 21521444569. The next prime is 21521444653. The reversal of 21521444611 is 11644412512.

It is an interprime number because it is at equal distance from previous prime (21521444569) and next prime (21521444653).

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 21521444611 - 2¹¹ = 21521442563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21521444671) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 236751 + ... + 314791.

It is an arithmetic number, because the mean of its divisors is an integer number (2718905238).

Almost surely, 2^21521444611 is an apocalyptic number.

21521444611 is a deficient number, since it is larger than the sum of its proper divisors (229797293).

21521444611 is an equidigital number, since it uses as much as digits as its factorization.

21521444611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80981.

The product of its digits is 7680, while the sum is 31.

The spelling of 21521444611 in words is "twenty-one billion, five hundred twenty-one million, four hundred forty-four thousand, six hundred eleven".