21000011051 has 2 divisors, whose sum is σ = 21000011052. Its totient is φ = 21000011050.

The previous prime is 21000011047. The next prime is 21000011059. The reversal of 21000011051 is 15011000012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21000011051 - 2² = 21000011047 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000011059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500005525 + 10500005526.

It is an arithmetic number, because the mean of its divisors is an integer number (10500005526).

Almost surely, 2^21000011051 is an apocalyptic number.

21000011051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000011051 is an equidigital number, since it uses as much as digits as its factorization.

21000011051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10, while the sum is 11.

Adding to 21000011051 its reverse (15011000012), we get a palindrome (36011011063).

The spelling of 21000011051 in words is "twenty-one billion, eleven thousand, fifty-one".