644231342 has 4 divisors (see below), whose sum is σ = 966347016. Its totient is φ = 322115670.

The previous prime is 644231339. The next prime is 644231381. The reversal of 644231342 is 243132446.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161057834 + ... + 161057837.

It is an arithmetic number, because the mean of its divisors is an integer number (241586754).

Almost surely, 2^644231342 is an apocalyptic number.

644231342 is a deficient number, since it is larger than the sum of its proper divisors (322115674).

644231342 is a wasteful number, since it uses less digits than its factorization.

644231342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322115673.

The product of its digits is 13824, while the sum is 29.

The square root of 644231342 is about 25381.7127475669. The cubic root of 644231342 is about 863.6689037356.

Adding to 644231342 its reverse (243132446), we get a palindrome (887363788).

The spelling of 644231342 in words is "six hundred forty-four million, two hundred thirty-one thousand, three hundred forty-two".