3928891005 has 24 divisors (see below), whose sum is σ = 7333930968. Its totient is φ = 1934222976.

The previous prime is 3928890967. The next prime is 3928891009. The reversal of 3928891005 is 5001988293.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2490084 + 3926400921 = 1578^2 + 62661^2 .

It is not a de Polignac number, because 3928891005 - 2⁷ = 3928890877 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3928891009) 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 23 ways as a sum of consecutive naturals, for example, 3357442 + ... + 3358611.

It is an arithmetic number, because the mean of its divisors is an integer number (305580457).

Almost surely, 2^3928891005 is an apocalyptic number.

It is an amenable number.

3928891005 is a deficient number, since it is larger than the sum of its proper divisors (3405039963).

3928891005 is a wasteful number, since it uses less digits than its factorization.

3928891005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6716077 (or 6716074 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The square root of 3928891005 is about 62680.8663389395. The cubic root of 3928891005 is about 1577.9382129181.

The spelling of 3928891005 in words is "three billion, nine hundred twenty-eight million, eight hundred ninety-one thousand, five".