21172892011 has 2 divisors, whose sum is σ = 21172892012. Its totient is φ = 21172892010.

The previous prime is 21172891981. The next prime is 21172892017. The reversal of 21172892011 is 11029827112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21172892011 is a prime.

It is a super-2 number, since 2×21172892011² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21172892017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10586446005 + 10586446006.

It is an arithmetic number, because the mean of its divisors is an integer number (10586446006).

Almost surely, 2^21172892011 is an apocalyptic number.

21172892011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21172892011 is an equidigital number, since it uses as much as digits as its factorization.

21172892011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 34.

The spelling of 21172892011 in words is "twenty-one billion, one hundred seventy-two million, eight hundred ninety-two thousand, eleven".