612721 has 4 divisors (see below), whose sum is σ = 616000. Its totient is φ = 609444.

The previous prime is 612719. The next prime is 612727. The reversal of 612721 is 127216.

612721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 612721 - 2¹ = 612719 is a prime.

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

It is a Duffinian number.

612721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (612727) 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, 1341 + ... + 1738.

It is an arithmetic number, because the mean of its divisors is an integer number (154000).

2⁶¹²⁷²¹ is an apocalyptic number.

It is an amenable number.

612721 is a deficient number, since it is larger than the sum of its proper divisors (3279).

612721 is a wasteful number, since it uses less digits than its factorization.

612721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3278.

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

The square root of 612721 is about 782.7649711120. The cubic root of 612721 is about 84.9351754882.

Adding to 612721 its reverse (127216), we get a palindrome (739937).

The spelling of 612721 in words is "six hundred twelve thousand, seven hundred twenty-one".