21356151571 has 2 divisors, whose sum is σ = 21356151572. Its totient is φ = 21356151570.

The previous prime is 21356151569. The next prime is 21356151611. The reversal of 21356151571 is 17515165312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21356151571 - 2¹ = 21356151569 is a prime.

Together with 21356151569, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21356151571.

It is not a weakly prime, because it can be changed into another prime (21356151871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678075785 + 10678075786.

It is an arithmetic number, because the mean of its divisors is an integer number (10678075786).

Almost surely, 2^21356151571 is an apocalyptic number.

21356151571 is a deficient number, since it is larger than the sum of its proper divisors (1).

21356151571 is an equidigital number, since it uses as much as digits as its factorization.

21356151571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31500, while the sum is 37.

The spelling of 21356151571 in words is "twenty-one billion, three hundred fifty-six million, one hundred fifty-one thousand, five hundred seventy-one".