21212016827 has 2 divisors, whose sum is σ = 21212016828. Its totient is φ = 21212016826.

The previous prime is 21212016797. The next prime is 21212016857. The reversal of 21212016827 is 72861021212.

It is a balanced prime because it is at equal distance from previous prime (21212016797) and next prime (21212016857).

It is a cyclic number.

It is not a de Polignac number, because 21212016827 - 2¹⁴ = 21212000443 is a prime.

It is a super-2 number, since 2×21212016827² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21212016793 and 21212016802.

It is not a weakly prime, because it can be changed into another prime (21212016857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606008413 + 10606008414.

It is an arithmetic number, because the mean of its divisors is an integer number (10606008414).

Almost surely, 2^21212016827 is an apocalyptic number.

21212016827 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212016827 is an equidigital number, since it uses as much as digits as its factorization.

21212016827 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 32.

The spelling of 21212016827 in words is "twenty-one billion, two hundred twelve million, sixteen thousand, eight hundred twenty-seven".