2156538 has 16 divisors (see below), whose sum is σ = 4540320. Its totient is φ = 680976.

The previous prime is 2156537. The next prime is 2156597. The reversal of 2156538 is 8356512.

It is a super-2 number, since 2×2156538² = 9301312290888, which contains 22 as substring.

It is a d-powerful number, because it can be written as 2¹⁴ + 1 + 5⁴ + 6⁷ + 5⁵ + 3¹³ + 8⁶ .

It is not an unprimeable number, because it can be changed into a prime (2156537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9345 + ... + 9572.

It is an arithmetic number, because the mean of its divisors is an integer number (283770).

2^2156538 is an apocalyptic number.

2156538 is an abundant number, since it is smaller than the sum of its proper divisors (2383782).

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

2156538 is a wasteful number, since it uses less digits than its factorization.

2156538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18941.

The product of its digits is 7200, while the sum is 30.

The square root of 2156538 is about 1468.5155770369. The cubic root of 2156538 is about 129.1969828713.

The spelling of 2156538 in words is "two million, one hundred fifty-six thousand, five hundred thirty-eight".