21111566051 has 8 divisors (see below), whose sum is σ = 21145924800. Its totient is φ = 21077235328.

The previous prime is 21111566041. The next prime is 21111566057. The reversal of 21111566051 is 15066511112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111566051 is a prime.

It is a super-2 number, since 2×21111566051² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111566057) 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, 1898630 + ... + 1909716.

It is an arithmetic number, because the mean of its divisors is an integer number (2643240600).

Almost surely, 2^21111566051 is an apocalyptic number.

21111566051 is a deficient number, since it is larger than the sum of its proper divisors (34358749).

21111566051 is a wasteful number, since it uses less digits than its factorization.

21111566051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14013.

The product of its (nonzero) digits is 1800, while the sum is 29.

The spelling of 21111566051 in words is "twenty-one billion, one hundred eleven million, five hundred sixty-six thousand, fifty-one".