6921913081 has 8 divisors (see below), whose sum is σ = 6985032840. Its totient is φ = 6858976128.

The previous prime is 6921913051. The next prime is 6921913147. The reversal of 6921913081 is 1803191296.

It can be written as a sum of positive squares in 4 ways, for example, as 1151991481 + 5769921600 = 33941^2 + 75960^2 .

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 6921913081 - 2²³ = 6913524473 is a prime.

It is a super-3 number, since 3×6921913081³ (a number of 30 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6921913051) 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, 30955 + ... + 121663.

It is an arithmetic number, because the mean of its divisors is an integer number (873129105).

Almost surely, 2^6921913081 is an apocalyptic number.

It is an amenable number.

6921913081 is a deficient number, since it is larger than the sum of its proper divisors (63119759).

6921913081 is a wasteful number, since it uses less digits than its factorization.

6921913081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91403.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 6921913081 is about 83198.0353193511. The cubic root of 6921913081 is about 1905.7914775473.

The spelling of 6921913081 in words is "six billion, nine hundred twenty-one million, nine hundred thirteen thousand, eighty-one".