21544212307 has 2 divisors, whose sum is σ = 21544212308. Its totient is φ = 21544212306.

The previous prime is 21544212301. The next prime is 21544212367. The reversal of 21544212307 is 70321244512.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21544212307 - 2²⁷ = 21409994579 is a prime.

It is not a weakly prime, because it can be changed into another prime (21544212301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10772106153 + 10772106154.

It is an arithmetic number, because the mean of its divisors is an integer number (10772106154).

Almost surely, 2^21544212307 is an apocalyptic number.

21544212307 is a deficient number, since it is larger than the sum of its proper divisors (1).

21544212307 is an equidigital number, since it uses as much as digits as its factorization.

21544212307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 31.

Adding to 21544212307 its reverse (70321244512), we get a palindrome (91865456819).

The spelling of 21544212307 in words is "twenty-one billion, five hundred forty-four million, two hundred twelve thousand, three hundred seven".