21087605347 has 2 divisors, whose sum is σ = 21087605348. Its totient is φ = 21087605346.

The previous prime is 21087605299. The next prime is 21087605351. The reversal of 21087605347 is 74350678012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21087605347 is a prime.

It is not a weakly prime, because it can be changed into another prime (21087605387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10543802673 + 10543802674.

It is an arithmetic number, because the mean of its divisors is an integer number (10543802674).

Almost surely, 2^21087605347 is an apocalyptic number.

21087605347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21087605347 is an equidigital number, since it uses as much as digits as its factorization.

21087605347 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 282240, while the sum is 43.

The spelling of 21087605347 in words is "twenty-one billion, eighty-seven million, six hundred five thousand, three hundred forty-seven".