42782371921 has 21 divisors (see below), whose sum is σ = 47512791451. Its totient is φ = 38515076512.

The previous prime is 42782371889. The next prime is 42782371927. The reversal of 42782371921 is 12917328724.

The square root of 42782371921 is 206839.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 33308075025 + 9474296896 = 182505^2 + 97336^2 .

It is not a de Polignac number, because 42782371921 - 2⁵ = 42782371889 is a prime.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42782371927) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 1860103116 + ... + 1860103138.

Almost surely, 2^42782371921 is an apocalyptic number.

42782371921 is the 206839-th square number.

42782371921 is the 103420-th centered octagonal number.

It is an amenable number.

42782371921 is a deficient number, since it is larger than the sum of its proper divisors (4730419530).

42782371921 is an frugal number, since it uses more digits than its factorization.

42782371921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 40 counting only the distinct ones).

The product of its digits is 338688, while the sum is 46.

The spelling of 42782371921 in words is "forty-two billion, seven hundred eighty-two million, three hundred seventy-one thousand, nine hundred twenty-one".