21025143011611 has 32 divisors (see below), whose sum is σ = 21567478968000. Its totient is φ = 20489877946368.

The previous prime is 21025143011531. The next prime is 21025143011629. The reversal of 21025143011611 is 11611034152012.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21025143011611 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21025143011611.

It is not an unprimeable number, because it can be changed into a prime (21025143011011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5270778405 + ... + 5270782393.

It is an arithmetic number, because the mean of its divisors is an integer number (673983717750).

Almost surely, 2^{21025143011611} is an apocalyptic number.

21025143011611 is a deficient number, since it is larger than the sum of its proper divisors (542335956389).

21025143011611 is a wasteful number, since it uses less digits than its factorization.

21025143011611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5743.

The product of its (nonzero) digits is 1440, while the sum is 28.

Adding to 21025143011611 its reverse (11611034152012), we get a palindrome (32636177163623).

The spelling of 21025143011611 in words is "twenty-one trillion, twenty-five billion, one hundred forty-three million, eleven thousand, six hundred eleven".