646641031 has 4 divisors (see below), whose sum is σ = 652363632. Its totient is φ = 640918432.

The previous prime is 646641013. The next prime is 646641089. The reversal of 646641031 is 130146646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 646641031 - 2⁵ = 646640999 is a prime.

It is a super-2 number, since 2×646641031² = 836289245945485922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646640984 and 646641002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646641011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2861131 + ... + 2861356.

It is an arithmetic number, because the mean of its divisors is an integer number (163090908).

Almost surely, 2^646641031 is an apocalyptic number.

646641031 is a deficient number, since it is larger than the sum of its proper divisors (5722601).

646641031 is a wasteful number, since it uses less digits than its factorization.

646641031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5722600.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 646641031 is about 25429.1374411324. The cubic root of 646641031 is about 864.7443890395.

Adding to 646641031 its reverse (130146646), we get a palindrome (776787677).

The spelling of 646641031 in words is "six hundred forty-six million, six hundred forty-one thousand, thirty-one".