2145278538 has 48 divisors (see below), whose sum is σ = 5178274920. Its totient is φ = 637322112.

The previous prime is 2145278519. The next prime is 2145278549. The reversal of 2145278538 is 8358725412.

2145278538 is a `hidden beast` number, since 2 + 1 + 45 + 2 + 78 + 538 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2049101289 + 96177249 = 45267^2 + 9807^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2145278493 and 2145278502.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 151281 + ... + 164852.

Almost surely, 2^2145278538 is an apocalyptic number.

2145278538 is an abundant number, since it is smaller than the sum of its proper divisors (3032996382).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2145278538 is a wasteful number, since it uses less digits than its factorization.

2145278538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316183 (or 316180 counting only the distinct ones).

The product of its digits is 537600, while the sum is 45.

The square root of 2145278538 is about 46317.1516611287. The cubic root of 2145278538 is about 1289.7174106077.

The spelling of 2145278538 in words is "two billion, one hundred forty-five million, two hundred seventy-eight thousand, five hundred thirty-eight".