21212131019 has 2 divisors, whose sum is σ = 21212131020. Its totient is φ = 21212131018.

The previous prime is 21212130983. The next prime is 21212131049. The reversal of 21212131019 is 91013121212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21212131019 - 2³² = 16917163723 is a prime.

It is a super-2 number, since 2×21212131019² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21212130985 and 21212131003.

It is not a weakly prime, because it can be changed into another prime (21212131049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606065509 + 10606065510.

It is an arithmetic number, because the mean of its divisors is an integer number (10606065510).

Almost surely, 2^21212131019 is an apocalyptic number.

21212131019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212131019 is an equidigital number, since it uses as much as digits as its factorization.

21212131019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 23.

The spelling of 21212131019 in words is "twenty-one billion, two hundred twelve million, one hundred thirty-one thousand, nineteen".