644142695 has 16 divisors (see below), whose sum is σ = 894581760. Its totient is φ = 436104864.

The previous prime is 644142683. The next prime is 644142721. The reversal of 644142695 is 596241446.

It is a cyclic number.

It is not a de Polignac number, because 644142695 - 2⁴ = 644142679 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113717 + ... + 119246.

It is an arithmetic number, because the mean of its divisors is an integer number (55911360).

Almost surely, 2^644142695 is an apocalyptic number.

644142695 is a deficient number, since it is larger than the sum of its proper divisors (250439065).

644142695 is a wasteful number, since it uses less digits than its factorization.

644142695 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233054.

The product of its digits is 207360, while the sum is 41.

The square root of 644142695 is about 25379.9664105373. The cubic root of 644142695 is about 863.6292879618.

The spelling of 644142695 in words is "six hundred forty-four million, one hundred forty-two thousand, six hundred ninety-five".