640441212 has 12 divisors (see below), whose sum is σ = 1494362856. Its totient is φ = 213480400.

The previous prime is 640441201. The next prime is 640441231. The reversal of 640441212 is 212144046.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26685039 + ... + 26685062.

It is an arithmetic number, because the mean of its divisors is an integer number (124530238).

Almost surely, 2^640441212 is an apocalyptic number.

It is an amenable number.

640441212 is an abundant number, since it is smaller than the sum of its proper divisors (853921644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640441212 is a wasteful number, since it uses less digits than its factorization.

640441212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53370108 (or 53370106 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 640441212 is about 25306.9399967677. The cubic root of 640441212 is about 861.9718643638.

Adding to 640441212 its reverse (212144046), we get a palindrome (852585258).

It can be divided in two parts, 64044 and 1212, that added together give a palindrome (65256).

The spelling of 640441212 in words is "six hundred forty million, four hundred forty-one thousand, two hundred twelve".