678721611 has 16 divisors (see below), whose sum is σ = 913575168. Its totient is φ = 448188000.

The previous prime is 678721609. The next prime is 678721633. The reversal of 678721611 is 116127876.

It is not a de Polignac number, because 678721611 - 2¹ = 678721609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 678721611.

It is not an unprimeable number, because it can be changed into a prime (678721411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 264786 + ... + 267336.

It is an arithmetic number, because the mean of its divisors is an integer number (57098448).

Almost surely, 2^678721611 is an apocalyptic number.

678721611 is a deficient number, since it is larger than the sum of its proper divisors (234853557).

678721611 is a wasteful number, since it uses less digits than its factorization.

678721611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3362.

The product of its digits is 28224, while the sum is 39.

The square root of 678721611 is about 26052.2860993042. The cubic root of 678721611 is about 878.8145241624.

The spelling of 678721611 in words is "six hundred seventy-eight million, seven hundred twenty-one thousand, six hundred eleven".