617650721 has 4 divisors (see below), whose sum is σ = 622365744. Its totient is φ = 612935700.

The previous prime is 617650703. The next prime is 617650741. The reversal of 617650721 is 127056716.

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 617650721 - 2¹⁴ = 617634337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (617650741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2357315 + ... + 2357576.

It is an arithmetic number, because the mean of its divisors is an integer number (155591436).

Almost surely, 2^617650721 is an apocalyptic number.

It is an amenable number.

617650721 is a deficient number, since it is larger than the sum of its proper divisors (4715023).

617650721 is a wasteful number, since it uses less digits than its factorization.

617650721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4715022.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 617650721 is about 24852.5797654891. The cubic root of 617650721 is about 851.6235272557.

The spelling of 617650721 in words is "six hundred seventeen million, six hundred fifty thousand, seven hundred twenty-one".