15212021213 has 2 divisors, whose sum is σ = 15212021214. Its totient is φ = 15212021212.

The previous prime is 15212021203. The next prime is 15212021219. The reversal of 15212021213 is 31212021251.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8602006009 + 6610015204 = 92747^2 + 81302^2 .

It is a cyclic number.

It is not a de Polignac number, because 15212021213 - 2²⁴ = 15195243997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15212021219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7606010606 + 7606010607.

It is an arithmetic number, because the mean of its divisors is an integer number (7606010607).

Almost surely, 2^15212021213 is an apocalyptic number.

It is an amenable number.

15212021213 is a deficient number, since it is larger than the sum of its proper divisors (1).

15212021213 is an equidigital number, since it uses as much as digits as its factorization.

15212021213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 15212021213 its reverse (31212021251), we get a palindrome (46424042464).

The spelling of 15212021213 in words is "fifteen billion, two hundred twelve million, twenty-one thousand, two hundred thirteen".