644661742412 has 24 divisors (see below), whose sum is σ = 1155726653760. Its totient is φ = 314454842240.

The previous prime is 644661742399. The next prime is 644661742427. The reversal of 644661742412 is 214247166446.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4134818 + ... + 4287894.

It is an arithmetic number, because the mean of its divisors is an integer number (48155277240).

Almost surely, 2^644661742412 is an apocalyptic number.

It is an amenable number.

644661742412 is a deficient number, since it is larger than the sum of its proper divisors (511064911348).

644661742412 is a wasteful number, since it uses less digits than its factorization.

644661742412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178801 (or 178799 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 47.

The spelling of 644661742412 in words is "six hundred forty-four billion, six hundred sixty-one million, seven hundred forty-two thousand, four hundred twelve".