21951876439 has 2 divisors, whose sum is σ = 21951876440. Its totient is φ = 21951876438.

The previous prime is 21951876421. The next prime is 21951876469. The reversal of 21951876439 is 93467815912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21951876439 - 2¹³ = 21951868247 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21951876439.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21951876469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10975938219 + 10975938220.

It is an arithmetic number, because the mean of its divisors is an integer number (10975938220).

Almost surely, 2^21951876439 is an apocalyptic number.

21951876439 is a deficient number, since it is larger than the sum of its proper divisors (1).

21951876439 is an equidigital number, since it uses as much as digits as its factorization.

21951876439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3265920, while the sum is 55.

The spelling of 21951876439 in words is "twenty-one billion, nine hundred fifty-one million, eight hundred seventy-six thousand, four hundred thirty-nine".