21287648733427 has 2 divisors, whose sum is σ = 21287648733428. Its totient is φ = 21287648733426.

The previous prime is 21287648733301. The next prime is 21287648733473. The reversal of 21287648733427 is 72433784678212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21287648733427 is a prime.

It is not a weakly prime, because it can be changed into another prime (21287648733487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10643824366713 + 10643824366714.

It is an arithmetic number, because the mean of its divisors is an integer number (10643824366714).

Almost surely, 2^{21287648733427} is an apocalyptic number.

21287648733427 is a deficient number, since it is larger than the sum of its proper divisors (1).

21287648733427 is an equidigital number, since it uses as much as digits as its factorization.

21287648733427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 151732224, while the sum is 64.

The spelling of 21287648733427 in words is "twenty-one trillion, two hundred eighty-seven billion, six hundred forty-eight million, seven hundred thirty-three thousand, four hundred twenty-seven".