644624542 has 8 divisors (see below), whose sum is σ = 1008977616. Its totient is φ = 308298672.

The previous prime is 644624537. The next prime is 644624543. The reversal of 644624542 is 245426446.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644624543) 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, 7006743 + ... + 7006834.

It is an arithmetic number, because the mean of its divisors is an integer number (126122202).

Almost surely, 2^644624542 is an apocalyptic number.

644624542 is a deficient number, since it is larger than the sum of its proper divisors (364353074).

644624542 is a wasteful number, since it uses less digits than its factorization.

644624542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14013602.

The product of its digits is 184320, while the sum is 37.

The square root of 644624542 is about 25389.4573002260. The cubic root of 644624542 is about 863.8445784893.

The spelling of 644624542 in words is "six hundred forty-four million, six hundred twenty-four thousand, five hundred forty-two".