21887461571 has 2 divisors, whose sum is σ = 21887461572. Its totient is φ = 21887461570.

The previous prime is 21887461567. The next prime is 21887461579. The reversal of 21887461571 is 17516478812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21887461571 - 2² = 21887461567 is a prime.

It is not a weakly prime, because it can be changed into another prime (21887461579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10943730785 + 10943730786.

It is an arithmetic number, because the mean of its divisors is an integer number (10943730786).

Almost surely, 2^21887461571 is an apocalyptic number.

21887461571 is a deficient number, since it is larger than the sum of its proper divisors (1).

21887461571 is an equidigital number, since it uses as much as digits as its factorization.

21887461571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 752640, while the sum is 50.

The spelling of 21887461571 in words is "twenty-one billion, eight hundred eighty-seven million, four hundred sixty-one thousand, five hundred seventy-one".