21140893447 has 2 divisors, whose sum is σ = 21140893448. Its totient is φ = 21140893446.

The previous prime is 21140893429. The next prime is 21140893453. The reversal of 21140893447 is 74439804112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21140893447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21140893547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570446723 + 10570446724.

It is an arithmetic number, because the mean of its divisors is an integer number (10570446724).

Almost surely, 2^21140893447 is an apocalyptic number.

21140893447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21140893447 is an equidigital number, since it uses as much as digits as its factorization.

21140893447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 193536, while the sum is 43.

The spelling of 21140893447 in words is "twenty-one billion, one hundred forty million, eight hundred ninety-three thousand, four hundred forty-seven".