634387421 has 8 divisors (see below), whose sum is σ = 637169400. Its totient is φ = 631611648.

The previous prime is 634387399. The next prime is 634387427. The reversal of 634387421 is 124783436.

It can be written as a sum of positive squares in 4 ways, for example, as 59059225 + 575328196 = 7685^2 + 23986^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 634387421 - 2²² = 630193117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (634387427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 382025 + ... + 383681.

It is an arithmetic number, because the mean of its divisors is an integer number (79646175).

Almost surely, 2^634387421 is an apocalyptic number.

It is an amenable number.

634387421 is a deficient number, since it is larger than the sum of its proper divisors (2781979).

634387421 is a wasteful number, since it uses less digits than its factorization.

634387421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3103.

The product of its digits is 96768, while the sum is 38.

The square root of 634387421 is about 25187.0486758572. The cubic root of 634387421 is about 859.2473227858.

The spelling of 634387421 in words is "six hundred thirty-four million, three hundred eighty-seven thousand, four hundred twenty-one".