21001141247 has 2 divisors, whose sum is σ = 21001141248. Its totient is φ = 21001141246.

The previous prime is 21001141243. The next prime is 21001141349. The reversal of 21001141247 is 74214110012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21001141247 - 2² = 21001141243 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001141241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500570623 + 10500570624.

It is an arithmetic number, because the mean of its divisors is an integer number (10500570624).

Almost surely, 2^21001141247 is an apocalyptic number.

21001141247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001141247 is an equidigital number, since it uses as much as digits as its factorization.

21001141247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 23.

Adding to 21001141247 its reverse (74214110012), we get a palindrome (95215251259).

The spelling of 21001141247 in words is "twenty-one billion, one million, one hundred forty-one thousand, two hundred forty-seven".