3994721687 has 8 divisors (see below), whose sum is σ = 4475659152. Its totient is φ = 3533414400.

The previous prime is 3994721669. The next prime is 3994721723. The reversal of 3994721687 is 7861274993.

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 3994721687 - 2¹⁰ = 3994720663 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 (3994721617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4907114 + ... + 4907927.

It is an arithmetic number, because the mean of its divisors is an integer number (559457394).

Almost surely, 2^3994721687 is an apocalyptic number.

3994721687 is a gapful number since it is divisible by the number (37) formed by its first and last digit.

3994721687 is a deficient number, since it is larger than the sum of its proper divisors (480937465).

3994721687 is a wasteful number, since it uses less digits than its factorization.

3994721687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9815089.

The product of its digits is 4572288, while the sum is 56.

The square root of 3994721687 is about 63203.8106999887. The cubic root of 3994721687 is about 1586.7025113176.

The spelling of 3994721687 in words is "three billion, nine hundred ninety-four million, seven hundred twenty-one thousand, six hundred eighty-seven".