634431156256621 has 4 divisors (see below), whose sum is σ = 634431845216992. Its totient is φ = 634430467296252.

The previous prime is 634431156256567. The next prime is 634431156256637. The reversal of 634431156256621 is 126652651134436.

634431156256621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 634431156256621 - 2¹⁷ = 634431156125549 is a prime.

It is a super-2 number, since 2×634431156256621² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (634431156256921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 343097055 + ... + 344941228.

It is an arithmetic number, because the mean of its divisors is an integer number (158607961304248).

Almost surely, 2^{634431156256621} is an apocalyptic number.

It is an amenable number.

634431156256621 is a deficient number, since it is larger than the sum of its proper divisors (688960371).

634431156256621 is an equidigital number, since it uses as much as digits as its factorization.

634431156256621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688960370.

The product of its digits is 18662400, while the sum is 55.

The spelling of 634431156256621 in words is "six hundred thirty-four trillion, four hundred thirty-one billion, one hundred fifty-six million, two hundred fifty-six thousand, six hundred twenty-one".