212951621 has 2 divisors, whose sum is σ = 212951622. Its totient is φ = 212951620.

The previous prime is 212951597. The next prime is 212951623. The reversal of 212951621 is 126159212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 212868100 + 83521 = 14590^2 + 289^2 .

It is a cyclic number.

It is not a de Polignac number, because 212951621 - 2²⁶ = 145842757 is a prime.

Together with 212951623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212951623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106475810 + 106475811.

It is an arithmetic number, because the mean of its divisors is an integer number (106475811).

Almost surely, 2^212951621 is an apocalyptic number.

It is an amenable number.

212951621 is a deficient number, since it is larger than the sum of its proper divisors (1).

212951621 is an equidigital number, since it uses as much as digits as its factorization.

212951621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 29.

The square root of 212951621 is about 14592.8619879721. The cubic root of 212951621 is about 597.1640435560.

The spelling of 212951621 in words is "two hundred twelve million, nine hundred fifty-one thousand, six hundred twenty-one".