646544101 has 4 divisors (see below), whose sum is σ = 738907552. Its totient is φ = 554180652.

The previous prime is 646544089. The next prime is 646544111. The reversal of 646544101 is 101445646.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 646544101 - 2⁵ = 646544069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646544111) 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, 46181715 + ... + 46181728.

It is an arithmetic number, because the mean of its divisors is an integer number (184726888).

Almost surely, 2^646544101 is an apocalyptic number.

It is an amenable number.

646544101 is a deficient number, since it is larger than the sum of its proper divisors (92363451).

646544101 is an equidigital number, since it uses as much as digits as its factorization.

646544101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92363450.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 646544101 is about 25427.2314851617. The cubic root of 646544101 is about 864.7011791502.

Adding to 646544101 its reverse (101445646), we get a palindrome (747989747).

The spelling of 646544101 in words is "six hundred forty-six million, five hundred forty-four thousand, one hundred one".