721612 has 12 divisors (see below), whose sum is σ = 1277640. Its totient is φ = 356576.

The previous prime is 721597. The next prime is 721613. The reversal of 721612 is 216127.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 721612.

It is not an unprimeable number, because it can be changed into a prime (721613) 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, 658 + ... + 1369.

It is an arithmetic number, because the mean of its divisors is an integer number (106470).

2⁷²¹⁶¹² is an apocalyptic number.

It is an amenable number.

721612 is a deficient number, since it is larger than the sum of its proper divisors (556028).

721612 is a wasteful number, since it uses less digits than its factorization.

721612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2120 (or 2118 counting only the distinct ones).

The product of its digits is 168, while the sum is 19.

The square root of 721612 is about 849.4774864586. The cubic root of 721612 is about 89.6949341893.

Adding to 721612 its reverse (216127), we get a palindrome (937739).

The spelling of 721612 in words is "seven hundred twenty-one thousand, six hundred twelve".