612991 has 4 divisors (see below), whose sum is σ = 627984. Its totient is φ = 598000.

The previous prime is 612977. The next prime is 613007. The reversal of 612991 is 199216.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-612991 is a prime.

It is a Duffinian number.

612991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (612971) 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 3 ways as a sum of consecutive naturals, for example, 7435 + ... + 7516.

It is an arithmetic number, because the mean of its divisors is an integer number (156996).

2⁶¹²⁹⁹¹ is an apocalyptic number.

612991 is a deficient number, since it is larger than the sum of its proper divisors (14993).

612991 is a wasteful number, since it uses less digits than its factorization.

612991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14992.

The product of its digits is 972, while the sum is 28.

The square root of 612991 is about 782.9374176778. The cubic root of 612991 is about 84.9476494254.

The spelling of 612991 in words is "six hundred twelve thousand, nine hundred ninety-one".