21496643525947 has 2 divisors, whose sum is σ = 21496643525948. Its totient is φ = 21496643525946.

The previous prime is 21496643525933. The next prime is 21496643526011. The reversal of 21496643525947 is 74952534669412.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21496643525947 is a prime.

It is not a weakly prime, because it can be changed into another prime (21496643525047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10748321762973 + 10748321762974.

It is an arithmetic number, because the mean of its divisors is an integer number (10748321762974).

Almost surely, 2^{21496643525947} is an apocalyptic number.

21496643525947 is a deficient number, since it is larger than the sum of its proper divisors (1).

21496643525947 is an equidigital number, since it uses as much as digits as its factorization.

21496643525947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 391910400, while the sum is 67.

The spelling of 21496643525947 in words is "twenty-one trillion, four hundred ninety-six billion, six hundred forty-three million, five hundred twenty-five thousand, nine hundred forty-seven".