212011621 has 2 divisors, whose sum is σ = 212011622. Its totient is φ = 212011620.

The previous prime is 212011601. The next prime is 212011669. The reversal of 212011621 is 126110212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 171243396 + 40768225 = 13086^2 + 6385^2 .

It is a cyclic number.

It is not a de Polignac number, because 212011621 - 2²⁵ = 178457189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212011595 and 212011604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212011601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106005810 + 106005811.

It is an arithmetic number, because the mean of its divisors is an integer number (106005811).

Almost surely, 2^212011621 is an apocalyptic number.

It is an amenable number.

212011621 is a deficient number, since it is larger than the sum of its proper divisors (1).

212011621 is an equidigital number, since it uses as much as digits as its factorization.

212011621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 212011621 is about 14560.6188398708. The cubic root of 212011621 is about 596.2840906866.

Adding to 212011621 its reverse (126110212), we get a palindrome (338121833).

It can be divided in two parts, 21201 and 1621, that added together give a palindrome (22822).

The spelling of 212011621 in words is "two hundred twelve million, eleven thousand, six hundred twenty-one".