21151520015611 has 6 divisors (see below), whose sum is σ = 21906033215612. Its totient is φ = 20422157255640.

The previous prime is 21151520015599. The next prime is 21151520015627. The reversal of 21151520015611 is 11651002515112.

It is not a de Polignac number, because 21151520015611 - 2¹¹ = 21151520013563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21151520015641) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12575219145 + ... + 12575220826.

Almost surely, 2^{21151520015611} is an apocalyptic number.

21151520015611 is a deficient number, since it is larger than the sum of its proper divisors (754513200001).

21151520015611 is an equidigital number, since it uses as much as digits as its factorization.

21151520015611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25150440029 (or 25150440000 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 31.

The spelling of 21151520015611 in words is "twenty-one trillion, one hundred fifty-one billion, five hundred twenty million, fifteen thousand, six hundred eleven".