21278632871 has 2 divisors, whose sum is σ = 21278632872. Its totient is φ = 21278632870.

The previous prime is 21278632831. The next prime is 21278632877. The reversal of 21278632871 is 17823687212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21278632871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21278632877) 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, 10639316435 + 10639316436.

It is an arithmetic number, because the mean of its divisors is an integer number (10639316436).

Almost surely, 2^21278632871 is an apocalyptic number.

21278632871 is a deficient number, since it is larger than the sum of its proper divisors (1).

21278632871 is an equidigital number, since it uses as much as digits as its factorization.

21278632871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 451584, while the sum is 47.

The spelling of 21278632871 in words is "twenty-one billion, two hundred seventy-eight million, six hundred thirty-two thousand, eight hundred seventy-one".