634620643 has 4 divisors (see below), whose sum is σ = 634910400. Its totient is φ = 634330888.

The previous prime is 634620607. The next prime is 634620661. The reversal of 634620643 is 346026436.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 634620643 - 2¹⁷ = 634489571 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 634620599 and 634620608.

It is not an unprimeable number, because it can be changed into a prime (634620683) 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, 141568 + ... + 145981.

It is an arithmetic number, because the mean of its divisors is an integer number (158727600).

Almost surely, 2^634620643 is an apocalyptic number.

634620643 is a deficient number, since it is larger than the sum of its proper divisors (289757).

634620643 is a wasteful number, since it uses less digits than its factorization.

634620643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289756.

The product of its (nonzero) digits is 62208, while the sum is 34.

The square root of 634620643 is about 25191.6780504991. The cubic root of 634620643 is about 859.3526058879.

The spelling of 634620643 in words is "six hundred thirty-four million, six hundred twenty thousand, six hundred forty-three".