21157176071 has 2 divisors, whose sum is σ = 21157176072. Its totient is φ = 21157176070.

The previous prime is 21157176041. The next prime is 21157176119. The reversal of 21157176071 is 17067175112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21157176071 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21157176041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10578588035 + 10578588036.

It is an arithmetic number, because the mean of its divisors is an integer number (10578588036).

Almost surely, 2^21157176071 is an apocalyptic number.

21157176071 is a deficient number, since it is larger than the sum of its proper divisors (1).

21157176071 is an equidigital number, since it uses as much as digits as its factorization.

21157176071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20580, while the sum is 38.

The spelling of 21157176071 in words is "twenty-one billion, one hundred fifty-seven million, one hundred seventy-six thousand, seventy-one".