612721640 has 32 divisors (see below), whose sum is σ = 1379700000. Its totient is φ = 244897344.

The previous prime is 612721619. The next prime is 612721649. The reversal of 612721640 is 46127216.

It is not an unprimeable number, because it can be changed into a prime (612721649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53111 + ... + 63609.

It is an arithmetic number, because the mean of its divisors is an integer number (43115625).

Almost surely, 2^612721640 is an apocalyptic number.

It is an amenable number.

612721640 is an abundant number, since it is smaller than the sum of its proper divisors (766978360).

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

612721640 is a wasteful number, since it uses less digits than its factorization.

612721640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11969 (or 11965 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 612721640 is about 24753.2147407160. The cubic root of 612721640 is about 849.3520506040.

Adding to 612721640 its reverse (46127216), we get a palindrome (658848856).

The spelling of 612721640 in words is "six hundred twelve million, seven hundred twenty-one thousand, six hundred forty".