2138728 has 8 divisors (see below), whose sum is σ = 4010130. Its totient is φ = 1069360.

The previous prime is 2138713. The next prime is 2138737. The reversal of 2138728 is 8278312.

It can be written as a sum of positive squares in only one way, i.e., 1258884 + 879844 = 1122^2 + 938^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 2138728.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133663 + ... + 133678.

2^2138728 is an apocalyptic number.

It is an amenable number.

2138728 is a deficient number, since it is larger than the sum of its proper divisors (1871402).

2138728 is a wasteful number, since it uses less digits than its factorization.

2138728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267347 (or 267343 counting only the distinct ones).

The product of its digits is 5376, while the sum is 31.

The square root of 2138728 is about 1462.4390585594. The cubic root of 2138728 is about 128.8403368897.

The spelling of 2138728 in words is "two million, one hundred thirty-eight thousand, seven hundred twenty-eight".