212121961 has 2 divisors, whose sum is σ = 212121962. Its totient is φ = 212121960.

The previous prime is 212121929. The next prime is 212121983. The reversal of 212121961 is 169121212.

It is a happy number.

212121961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 139122025 + 72999936 = 11795^2 + 8544^2 .

It is a cyclic number.

It is not a de Polignac number, because 212121961 - 2⁵ = 212121929 is a prime.

It is not a weakly prime, because it can be changed into another prime (212121911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106060980 + 106060981.

It is an arithmetic number, because the mean of its divisors is an integer number (106060981).

Almost surely, 2^212121961 is an apocalyptic number.

It is an amenable number.

212121961 is a deficient number, since it is larger than the sum of its proper divisors (1).

212121961 is an equidigital number, since it uses as much as digits as its factorization.

212121961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 25.

The square root of 212121961 is about 14564.4073343202. The cubic root of 212121961 is about 596.3875167403.

The spelling of 212121961 in words is "two hundred twelve million, one hundred twenty-one thousand, nine hundred sixty-one".