15972130021 has 2 divisors, whose sum is σ = 15972130022. Its totient is φ = 15972130020.

The previous prime is 15972129997. The next prime is 15972130033. The reversal of 15972130021 is 12003127951.

15972130021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9311285025 + 6660844996 = 96495^2 + 81614^2 .

It is a cyclic number.

It is not a de Polignac number, because 15972130021 - 2¹¹ = 15972127973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15972130091) 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, 7986065010 + 7986065011.

It is an arithmetic number, because the mean of its divisors is an integer number (7986065011).

Almost surely, 2^15972130021 is an apocalyptic number.

It is an amenable number.

15972130021 is a deficient number, since it is larger than the sum of its proper divisors (1).

15972130021 is an equidigital number, since it uses as much as digits as its factorization.

15972130021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780, while the sum is 31.

Adding to 15972130021 its reverse (12003127951), we get a palindrome (27975257972).

The spelling of 15972130021 in words is "fifteen billion, nine hundred seventy-two million, one hundred thirty thousand, twenty-one".