21321974647 has 2 divisors, whose sum is σ = 21321974648. Its totient is φ = 21321974646.

The previous prime is 21321974593. The next prime is 21321974701. The reversal of 21321974647 is 74647912312.

It is a balanced prime because it is at equal distance from previous prime (21321974593) and next prime (21321974701).

It is a cyclic number.

It is not a de Polignac number, because 21321974647 - 2³¹ = 19174490999 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21321974597 and 21321974606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21321924647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660987323 + 10660987324.

It is an arithmetic number, because the mean of its divisors is an integer number (10660987324).

Almost surely, 2^21321974647 is an apocalyptic number.

21321974647 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321974647 is an equidigital number, since it uses as much as digits as its factorization.

21321974647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 46.

The spelling of 21321974647 in words is "twenty-one billion, three hundred twenty-one million, nine hundred seventy-four thousand, six hundred forty-seven".