21210212002157 has 2 divisors, whose sum is σ = 21210212002158. Its totient is φ = 21210212002156.

The previous prime is 21210212002141. The next prime is 21210212002183. The reversal of 21210212002157 is 75120021201212.

It is an a-pointer prime, because the next prime (21210212002183) can be obtained adding 21210212002157 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12255957724201 + 8954254277956 = 3500851^2 + 2992366^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210212002157 - 2⁴ = 21210212002141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210212002957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605106001078 + 10605106001079.

It is an arithmetic number, because the mean of its divisors is an integer number (10605106001079).

Almost surely, 2^{21210212002157} is an apocalyptic number.

It is an amenable number.

21210212002157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210212002157 is an equidigital number, since it uses as much as digits as its factorization.

21210212002157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 26.

Adding to 21210212002157 its reverse (75120021201212), we get a palindrome (96330233203369).

The spelling of 21210212002157 in words is "twenty-one trillion, two hundred ten billion, two hundred twelve million, two thousand, one hundred fifty-seven".