21980219771 has 2 divisors, whose sum is σ = 21980219772. Its totient is φ = 21980219770.

The previous prime is 21980219713. The next prime is 21980219783. The reversal of 21980219771 is 17791208912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21980219771 - 2¹⁸ = 21979957627 is a prime.

It is a super-2 number, since 2×21980219771² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21980219791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10990109885 + 10990109886.

It is an arithmetic number, because the mean of its divisors is an integer number (10990109886).

Almost surely, 2^21980219771 is an apocalyptic number.

21980219771 is a deficient number, since it is larger than the sum of its proper divisors (1).

21980219771 is an equidigital number, since it uses as much as digits as its factorization.

21980219771 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 127008, while the sum is 47.

The spelling of 21980219771 in words is "twenty-one billion, nine hundred eighty million, two hundred nineteen thousand, seven hundred seventy-one".