644692083 has 16 divisors (see below), whose sum is σ = 988650240. Its totient is φ = 366047136.

The previous prime is 644692073. The next prime is 644692109. The reversal of 644692083 is 380296446.

It is a happy number.

It is not a de Polignac number, because 644692083 - 2⁴ = 644692067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644692063) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94473 + ... + 101066.

It is an arithmetic number, because the mean of its divisors is an integer number (61790640).

Almost surely, 2^644692083 is an apocalyptic number.

644692083 is a deficient number, since it is larger than the sum of its proper divisors (343958157).

644692083 is a wasteful number, since it uses less digits than its factorization.

644692083 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195706.

The product of its (nonzero) digits is 248832, while the sum is 42.

The square root of 644692083 is about 25390.7873647116. The cubic root of 644692083 is about 863.8747474146.

The spelling of 644692083 in words is "six hundred forty-four million, six hundred ninety-two thousand, eighty-three".