21519231443 has 2 divisors, whose sum is σ = 21519231444. Its totient is φ = 21519231442.

The previous prime is 21519231401. The next prime is 21519231473. The reversal of 21519231443 is 34413291512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21519231443 - 2⁶ = 21519231379 is a prime.

It is not a weakly prime, because it can be changed into another prime (21519231473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10759615721 + 10759615722.

It is an arithmetic number, because the mean of its divisors is an integer number (10759615722).

Almost surely, 2^21519231443 is an apocalyptic number.

21519231443 is a deficient number, since it is larger than the sum of its proper divisors (1).

21519231443 is an equidigital number, since it uses as much as digits as its factorization.

21519231443 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 35.

The spelling of 21519231443 in words is "twenty-one billion, five hundred nineteen million, two hundred thirty-one thousand, four hundred forty-three".