21221020000157 has 2 divisors, whose sum is σ = 21221020000158. Its totient is φ = 21221020000156.

The previous prime is 21221020000069. The next prime is 21221020000171. The reversal of 21221020000157 is 75100002012212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19277842547716 + 1943177452441 = 4390654^2 + 1393979^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221020000157 - 2²⁶ = 21220952891293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221020000357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610510000078 + 10610510000079.

It is an arithmetic number, because the mean of its divisors is an integer number (10610510000079).

Almost surely, 2^{21221020000157} is an apocalyptic number.

It is an amenable number.

21221020000157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221020000157 is an equidigital number, since it uses as much as digits as its factorization.

21221020000157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 560, while the sum is 23.

Adding to 21221020000157 its reverse (75100002012212), we get a palindrome (96321022012369).

The spelling of 21221020000157 in words is "twenty-one trillion, two hundred twenty-one billion, twenty million, one hundred fifty-seven", and thus it is an aban number.