680721919 has 8 divisors (see below), whose sum is σ = 685645632. Its totient is φ = 675816480.

The previous prime is 680721917. The next prime is 680721989. The reversal of 680721919 is 919127086.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 680721919 - 2¹ = 680721917 is a prime.

It is a super-2 number, since 2×680721919² = 926764662014085122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (680721917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75117 + ... + 83689.

It is an arithmetic number, because the mean of its divisors is an integer number (85705704).

Almost surely, 2^680721919 is an apocalyptic number.

680721919 is a deficient number, since it is larger than the sum of its proper divisors (4923713).

680721919 is a wasteful number, since it uses less digits than its factorization.

680721919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9137.

The product of its (nonzero) digits is 54432, while the sum is 43.

The square root of 680721919 is about 26090.6481138357. The cubic root of 680721919 is about 879.6770160264.

The spelling of 680721919 in words is "six hundred eighty million, seven hundred twenty-one thousand, nine hundred nineteen".