644102061 has 8 divisors (see below), whose sum is σ = 859229280. Its totient is φ = 429188112.

The previous prime is 644102059. The next prime is 644102083. The reversal of 644102061 is 160201446.

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

It is not a de Polignac number, because 644102061 - 2¹ = 644102059 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644102561) 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, 46131 + ... + 58448.

It is an arithmetic number, because the mean of its divisors is an integer number (107403660).

Almost surely, 2^644102061 is an apocalyptic number.

It is an amenable number.

644102061 is a deficient number, since it is larger than the sum of its proper divisors (215127219).

644102061 is a wasteful number, since it uses less digits than its factorization.

644102061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106635.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 644102061 is about 25379.1658846385. The cubic root of 644102061 is about 863.6111276739.

The spelling of 644102061 in words is "six hundred forty-four million, one hundred two thousand, sixty-one".