611680021 has 4 divisors (see below), whose sum is σ = 612183852. Its totient is φ = 611176192.

The previous prime is 611679997. The next prime is 611680033. The reversal of 611680021 is 120086116.

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

It can be written as a sum of positive squares in 2 ways, for example, as 90060100 + 521619921 = 9490^2 + 22839^2 .

It is a cyclic number.

It is not a de Polignac number, because 611680021 - 2⁵ = 611679989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (611686021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 250090 + ... + 252523.

It is an arithmetic number, because the mean of its divisors is an integer number (153045963).

Almost surely, 2^611680021 is an apocalyptic number.

It is an amenable number.

611680021 is a deficient number, since it is larger than the sum of its proper divisors (503831).

611680021 is a wasteful number, since it uses less digits than its factorization.

611680021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503830.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 611680021 is about 24732.1657159255. The cubic root of 611680021 is about 848.8704817170.

The spelling of 611680021 in words is "six hundred eleven million, six hundred eighty thousand, twenty-one".