681502921 has 8 divisors (see below), whose sum is σ = 743648544. Its totient is φ = 619389120.

The previous prime is 681502909. The next prime is 681502951. The reversal of 681502921 is 129205186.

681502921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 681502921 - 2¹³ = 681494729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681502951) 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, 70630 + ... + 79696.

It is an arithmetic number, because the mean of its divisors is an integer number (92956068).

Almost surely, 2^681502921 is an apocalyptic number.

It is an amenable number.

681502921 is a deficient number, since it is larger than the sum of its proper divisors (62145623).

681502921 is a wasteful number, since it uses less digits than its factorization.

681502921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15911.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 681502921 is about 26105.6109103005. The cubic root of 681502921 is about 880.0133094578.

The spelling of 681502921 in words is "six hundred eighty-one million, five hundred two thousand, nine hundred twenty-one".