21133209947 has 2 divisors, whose sum is σ = 21133209948. Its totient is φ = 21133209946.

The previous prime is 21133209931. The next prime is 21133209953. The reversal of 21133209947 is 74990233112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21133209947 - 2⁴ = 21133209931 is a prime.

It is a super-2 number, since 2×21133209947² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21133209917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10566604973 + 10566604974.

It is an arithmetic number, because the mean of its divisors is an integer number (10566604974).

Almost surely, 2^21133209947 is an apocalyptic number.

21133209947 is a deficient number, since it is larger than the sum of its proper divisors (1).

21133209947 is an equidigital number, since it uses as much as digits as its factorization.

21133209947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 41.

The spelling of 21133209947 in words is "twenty-one billion, one hundred thirty-three million, two hundred nine thousand, nine hundred forty-seven".