21442401247 has 2 divisors, whose sum is σ = 21442401248. Its totient is φ = 21442401246.

The previous prime is 21442401187. The next prime is 21442401289. The reversal of 21442401247 is 74210424412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21442401247 - 2⁷ = 21442401119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21442411247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10721200623 + 10721200624.

It is an arithmetic number, because the mean of its divisors is an integer number (10721200624).

Almost surely, 2^21442401247 is an apocalyptic number.

21442401247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21442401247 is an equidigital number, since it uses as much as digits as its factorization.

21442401247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14336, while the sum is 31.

Adding to 21442401247 its reverse (74210424412), we get a palindrome (95652825659).

The spelling of 21442401247 in words is "twenty-one billion, four hundred forty-two million, four hundred one thousand, two hundred forty-seven".