21771002479 has 2 divisors, whose sum is σ = 21771002480. Its totient is φ = 21771002478.

The previous prime is 21771002453. The next prime is 21771002531. The reversal of 21771002479 is 97420017712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21771002479 - 2⁵ = 21771002447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21771003479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10885501239 + 10885501240.

It is an arithmetic number, because the mean of its divisors is an integer number (10885501240).

Almost surely, 2^21771002479 is an apocalyptic number.

21771002479 is a deficient number, since it is larger than the sum of its proper divisors (1).

21771002479 is an equidigital number, since it uses as much as digits as its factorization.

21771002479 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 49392, while the sum is 40.

The spelling of 21771002479 in words is "twenty-one billion, seven hundred seventy-one million, two thousand, four hundred seventy-nine".