3992878621 has 8 divisors (see below), whose sum is σ = 4242387960. Its totient is φ = 3757998784.

The previous prime is 3992878619. The next prime is 3992878639. The reversal of 3992878621 is 1268782993.

It can be written as a sum of positive squares in 4 ways, for example, as 1229273721 + 2763604900 = 35061^2 + 52570^2 .

It is not a de Polignac number, because 3992878621 - 2¹ = 3992878619 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 (3992872621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 401446 + ... + 411271.

It is an arithmetic number, because the mean of its divisors is an integer number (530298495).

Almost surely, 2^3992878621 is an apocalyptic number.

It is an amenable number.

3992878621 is a deficient number, since it is larger than the sum of its proper divisors (249509339).

3992878621 is an frugal number, since it uses more digits than its factorization.

3992878621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 812768 (or 812734 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 55.

The square root of 3992878621 is about 63189.2286786284. The cubic root of 3992878621 is about 1586.4584519860.

The spelling of 3992878621 in words is "three billion, nine hundred ninety-two million, eight hundred seventy-eight thousand, six hundred twenty-one".