3994492900721 has 4 divisors (see below), whose sum is σ = 4204729369200. Its totient is φ = 3784256432244.

The previous prime is 3994492900681. The next prime is 3994492900729. The reversal of 3994492900721 is 1270092944993.

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 3994492900721 - 2¹⁰ = 3994492899697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3994492900729) 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, 105118234211 + ... + 105118234248.

It is an arithmetic number, because the mean of its divisors is an integer number (1051182342300).

Almost surely, 2^{3994492900721} is an apocalyptic number.

It is an amenable number.

3994492900721 is a deficient number, since it is larger than the sum of its proper divisors (210236468479).

3994492900721 is a wasteful number, since it uses less digits than its factorization.

3994492900721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210236468478.

The product of its (nonzero) digits is 8817984, while the sum is 59.

The spelling of 3994492900721 in words is "three trillion, nine hundred ninety-four billion, four hundred ninety-two million, nine hundred thousand, seven hundred twenty-one".