634221811 has 2 divisors, whose sum is σ = 634221812. Its totient is φ = 634221810.

The previous prime is 634221787. The next prime is 634221821. The reversal of 634221811 is 118122436.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 634221811 - 2¹⁷ = 634090739 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 634221811.

It is not a weakly prime, because it can be changed into another prime (634221821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317110905 + 317110906.

It is an arithmetic number, because the mean of its divisors is an integer number (317110906).

Almost surely, 2^634221811 is an apocalyptic number.

634221811 is a deficient number, since it is larger than the sum of its proper divisors (1).

634221811 is an equidigital number, since it uses as much as digits as its factorization.

634221811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 28.

The square root of 634221811 is about 25183.7608589345. The cubic root of 634221811 is about 859.1725460122.

The spelling of 634221811 in words is "six hundred thirty-four million, two hundred twenty-one thousand, eight hundred eleven".