644016662 has 4 divisors (see below), whose sum is σ = 966024996. Its totient is φ = 322008330.

The previous prime is 644016649. The next prime is 644016673. The reversal of 644016662 is 266610446.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 266610446 = 2 ⋅133305223.

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, 161004164 + ... + 161004167.

It is an arithmetic number, because the mean of its divisors is an integer number (241506249).

Almost surely, 2^644016662 is an apocalyptic number.

644016662 is a deficient number, since it is larger than the sum of its proper divisors (322008334).

644016662 is a wasteful number, since it uses less digits than its factorization.

644016662 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322008333.

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 644016662 is about 25377.4833661654. The cubic root of 644016662 is about 863.5729583677.

The spelling of 644016662 in words is "six hundred forty-four million, sixteen thousand, six hundred sixty-two".