21220101201989 has 2 divisors, whose sum is σ = 21220101201990. Its totient is φ = 21220101201988.

The previous prime is 21220101201947. The next prime is 21220101202033. The reversal of 21220101201989 is 98910210102212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14670110304964 + 6549990897025 = 3830158^2 + 2559295^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220101201989 is a prime.

It is a super-2 number, since 2×21220101201989² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220101201289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610050600994 + 10610050600995.

It is an arithmetic number, because the mean of its divisors is an integer number (10610050600995).

Almost surely, 2^{21220101201989} is an apocalyptic number.

It is an amenable number.

21220101201989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220101201989 is an equidigital number, since it uses as much as digits as its factorization.

21220101201989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 38.

The spelling of 21220101201989 in words is "twenty-one trillion, two hundred twenty billion, one hundred one million, two hundred one thousand, nine hundred eighty-nine".