21772799989 has 2 divisors, whose sum is σ = 21772799990. Its totient is φ = 21772799988.

The previous prime is 21772799981. The next prime is 21772800001. The reversal of 21772799989 is 98999727712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15597512100 + 6175287889 = 124890^2 + 78583^2 .

It is a cyclic number.

It is not a de Polignac number, because 21772799989 - 2³ = 21772799981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21772799981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10886399994 + 10886399995.

It is an arithmetic number, because the mean of its divisors is an integer number (10886399995).

Almost surely, 2^21772799989 is an apocalyptic number.

It is an amenable number.

21772799989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21772799989 is an equidigital number, since it uses as much as digits as its factorization.

21772799989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72013536, while the sum is 70.

The spelling of 21772799989 in words is "twenty-one billion, seven hundred seventy-two million, seven hundred ninety-nine thousand, nine hundred eighty-nine".