215434861 has 2 divisors, whose sum is σ = 215434862. Its totient is φ = 215434860.

The previous prime is 215434853. The next prime is 215434867. The reversal of 215434861 is 168434512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211149961 + 4284900 = 14531^2 + 2070^2 .

It is a cyclic number.

It is not a de Polignac number, because 215434861 - 2³ = 215434853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215434867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107717430 + 107717431.

It is an arithmetic number, because the mean of its divisors is an integer number (107717431).

Almost surely, 2^215434861 is an apocalyptic number.

It is an amenable number.

215434861 is a deficient number, since it is larger than the sum of its proper divisors (1).

215434861 is an equidigital number, since it uses as much as digits as its factorization.

215434861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 34.

The square root of 215434861 is about 14677.6994450765. The cubic root of 215434861 is about 599.4762661192.

The spelling of 215434861 in words is "two hundred fifteen million, four hundred thirty-four thousand, eight hundred sixty-one".