634404251 has 4 divisors (see below), whose sum is σ = 683204592. Its totient is φ = 585603912.

The previous prime is 634404217. The next prime is 634404259. The reversal of 634404251 is 152404436.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-634404251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (634404259) 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, 24400151 + ... + 24400176.

It is an arithmetic number, because the mean of its divisors is an integer number (170801148).

Almost surely, 2^634404251 is an apocalyptic number.

634404251 is a deficient number, since it is larger than the sum of its proper divisors (48800341).

634404251 is a wasteful number, since it uses less digits than its factorization.

634404251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48800340.

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 634404251 is about 25187.3827739208. The cubic root of 634404251 is about 859.2549211944.

Adding to 634404251 its reverse (152404436), we get a palindrome (786808687).

The spelling of 634404251 in words is "six hundred thirty-four million, four hundred four thousand, two hundred fifty-one".