21012002047 has 2 divisors, whose sum is σ = 21012002048. Its totient is φ = 21012002046.

The previous prime is 21012002041. The next prime is 21012002117. The reversal of 21012002047 is 74020021012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21012002047 - 2¹¹ = 21011999999 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012002041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506001023 + 10506001024.

It is an arithmetic number, because the mean of its divisors is an integer number (10506001024).

Almost surely, 2^21012002047 is an apocalyptic number.

21012002047 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012002047 is an equidigital number, since it uses as much as digits as its factorization.

21012002047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 19.

Adding to 21012002047 its reverse (74020021012), we get a palindrome (95032023059).

The spelling of 21012002047 in words is "twenty-one billion, twelve million, two thousand, forty-seven".