6801631721 has 4 divisors (see below), whose sum is σ = 6805713552. Its totient is φ = 6797549892.

The previous prime is 6801631673. The next prime is 6801631729. The reversal of 6801631721 is 1271361086.

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 a de Polignac number, because none of the positive numbers 2^k-6801631721 is a prime.

It is a super-2 number, since 2×6801631721² = 92524388136226843682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6801631729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2038415 + ... + 2041748.

It is an arithmetic number, because the mean of its divisors is an integer number (1701428388).

Almost surely, 2^6801631721 is an apocalyptic number.

It is an amenable number.

6801631721 is a deficient number, since it is larger than the sum of its proper divisors (4081831).

6801631721 is a wasteful number, since it uses less digits than its factorization.

6801631721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4081830.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 6801631721 is about 82472.0056807157. The cubic root of 6801631721 is about 1894.6879992599.

The spelling of 6801631721 in words is "six billion, eight hundred one million, six hundred thirty-one thousand, seven hundred twenty-one".