21121100071 has 2 divisors, whose sum is σ = 21121100072. Its totient is φ = 21121100070.

The previous prime is 21121100047. The next prime is 21121100083. The reversal of 21121100071 is 17000112112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21121100071 - 2²³ = 21112711463 is a prime.

It is a super-2 number, since 2×21121100071² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121100471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560550035 + 10560550036.

It is an arithmetic number, because the mean of its divisors is an integer number (10560550036).

Almost surely, 2^21121100071 is an apocalyptic number.

21121100071 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121100071 is an equidigital number, since it uses as much as digits as its factorization.

21121100071 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28, while the sum is 16.

Adding to 21121100071 its reverse (17000112112), we get a palindrome (38121212183).

The spelling of 21121100071 in words is "twenty-one billion, one hundred twenty-one million, one hundred thousand, seventy-one".