634451621 has 2 divisors, whose sum is σ = 634451622. Its totient is φ = 634451620.

The previous prime is 634451581. The next prime is 634451633. The reversal of 634451621 is 126154436.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 587529121 + 46922500 = 24239^2 + 6850^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-634451621 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (634451641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317225810 + 317225811.

It is an arithmetic number, because the mean of its divisors is an integer number (317225811).

Almost surely, 2^634451621 is an apocalyptic number.

It is an amenable number.

634451621 is a deficient number, since it is larger than the sum of its proper divisors (1).

634451621 is an equidigital number, since it uses as much as digits as its factorization.

634451621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 32.

The square root of 634451621 is about 25188.3231081388. The cubic root of 634451621 is about 859.2763070813.

The spelling of 634451621 in words is "six hundred thirty-four million, four hundred fifty-one thousand, six hundred twenty-one".