21201515011 has 2 divisors, whose sum is σ = 21201515012. Its totient is φ = 21201515010.

The previous prime is 21201514987. The next prime is 21201515021. The reversal of 21201515011 is 11051510212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21201515011 - 2²³ = 21193126403 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21201515011.

It is not a weakly prime, because it can be changed into another prime (21201515021) 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 as a sum of consecutive naturals, namely, 10600757505 + 10600757506.

It is an arithmetic number, because the mean of its divisors is an integer number (10600757506).

Almost surely, 2^21201515011 is an apocalyptic number.

21201515011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201515011 is an equidigital number, since it uses as much as digits as its factorization.

21201515011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 100, while the sum is 19.

The spelling of 21201515011 in words is "twenty-one billion, two hundred one million, five hundred fifteen thousand, eleven".