21447604487 has 2 divisors, whose sum is σ = 21447604488. Its totient is φ = 21447604486.

The previous prime is 21447604471. The next prime is 21447604531. The reversal of 21447604487 is 78440674412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21447604487 - 2⁴ = 21447604471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21447604427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10723802243 + 10723802244.

It is an arithmetic number, because the mean of its divisors is an integer number (10723802244).

Almost surely, 2^21447604487 is an apocalyptic number.

21447604487 is a deficient number, since it is larger than the sum of its proper divisors (1).

21447604487 is an equidigital number, since it uses as much as digits as its factorization.

21447604487 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1204224, while the sum is 47.

The spelling of 21447604487 in words is "twenty-one billion, four hundred forty-seven million, six hundred four thousand, four hundred eighty-seven".