21110099971 has 2 divisors, whose sum is σ = 21110099972.
Its totient is φ = 21110099970.
The previous prime is 21110099909. The next prime is 21110100023. The reversal of 21110099971 is 17999001112.
It is a strong prime.
It is a cyclic number.
It is not a de Polignac number, because 21110099971 - 217 = 21109968899 is a prime.
It is a super-2 number, since 2×211100999712 (a number of 21 digits) contains 22 as substring.
It is not a weakly prime, because it can be changed into another prime (21110099671) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555049985 + 10555049986.
It is an arithmetic number, because the mean of its divisors is an integer number (10555049986).
Almost surely, 221110099971 is an apocalyptic number.
21110099971 is a deficient number, since it is larger than the sum of its proper divisors (1).
21110099971 is an equidigital number, since it uses as much as digits as its factorization.
21110099971 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 10206, while the sum is 40.
The spelling of 21110099971 in words is "twenty-one billion, one hundred ten million, ninety-nine thousand, nine hundred seventy-one".