634221787 has 2 divisors, whose sum is σ = 634221788. Its totient is φ = 634221786.

The previous prime is 634221781. The next prime is 634221811. The reversal of 634221787 is 787122436.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 634221787 - 2²³ = 625833179 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (634221781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317110893 + 317110894.

It is an arithmetic number, because the mean of its divisors is an integer number (317110894).

Almost surely, 2^634221787 is an apocalyptic number.

634221787 is a deficient number, since it is larger than the sum of its proper divisors (1).

634221787 is an equidigital number, since it uses as much as digits as its factorization.

634221787 is an evil number, because the sum of its binary digits is even.

The product of its digits is 112896, while the sum is 40.

The square root of 634221787 is about 25183.7603824369. The cubic root of 634221787 is about 859.1725351747.

The spelling of 634221787 in words is "six hundred thirty-four million, two hundred twenty-one thousand, seven hundred eighty-seven".