21212001511 has 2 divisors, whose sum is σ = 21212001512. Its totient is φ = 21212001510.

The previous prime is 21212001497. The next prime is 21212001553. The reversal of 21212001511 is 11510021212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21212001511 - 2¹¹ = 21211999463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212901511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606000755 + 10606000756.

It is an arithmetic number, because the mean of its divisors is an integer number (10606000756).

Almost surely, 2^21212001511 is an apocalyptic number.

21212001511 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212001511 is an equidigital number, since it uses as much as digits as its factorization.

21212001511 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40, while the sum is 16.

Adding to 21212001511 its reverse (11510021212), we get a palindrome (32722022723).

The spelling of 21212001511 in words is "twenty-one billion, two hundred twelve million, one thousand, five hundred eleven".