20010021197 has 2 divisors, whose sum is σ = 20010021198. Its totient is φ = 20010021196.

The previous prime is 20010021169. The next prime is 20010021203. The reversal of 20010021197 is 79112001002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16943187556 + 3066833641 = 130166^2 + 55379^2 .

It is a cyclic number.

It is not a de Polignac number, because 20010021197 - 2⁸ = 20010020941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20010021797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005010598 + 10005010599.

It is an arithmetic number, because the mean of its divisors is an integer number (10005010599).

Almost surely, 2^20010021197 is an apocalyptic number.

It is an amenable number.

20010021197 is a deficient number, since it is larger than the sum of its proper divisors (1).

20010021197 is an equidigital number, since it uses as much as digits as its factorization.

20010021197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 23.

Adding to 20010021197 its reverse (79112001002), we get a palindrome (99122022199).

The spelling of 20010021197 in words is "twenty billion, ten million, twenty-one thousand, one hundred ninety-seven".