6718940021 has 4 divisors (see below), whose sum is σ = 7011067872. Its totient is φ = 6426812172.

The previous prime is 6718940003. The next prime is 6718940027. The reversal of 6718940021 is 1200498176.

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 not a de Polignac number, because 6718940021 - 2¹⁴ = 6718923637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6718940027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 146063891 + ... + 146063936.

It is an arithmetic number, because the mean of its divisors is an integer number (1752766968).

Almost surely, 2^6718940021 is an apocalyptic number.

It is an amenable number.

6718940021 is a deficient number, since it is larger than the sum of its proper divisors (292127851).

6718940021 is a wasteful number, since it uses less digits than its factorization.

6718940021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292127850.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 6718940021 is about 81969.1406628129. The cubic root of 6718940021 is about 1886.9783675334.

The spelling of 6718940021 in words is "six billion, seven hundred eighteen million, nine hundred forty thousand, twenty-one".