2156243125 has 10 divisors (see below), whose sum is σ = 2694442190. Its totient is φ = 1724994000.

The previous prime is 2156243083. The next prime is 2156243179. The reversal of 2156243125 is 5213426512.

It can be written as a sum of positive squares in 5 ways, for example, as 514291684 + 1641951441 = 22678^2 + 40521^2 .

It is not a de Polignac number, because 2156243125 - 2⁷ = 2156242997 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1724370 + ... + 1725619.

It is an arithmetic number, because the mean of its divisors is an integer number (269444219).

Almost surely, 2^2156243125 is an apocalyptic number.

2156243125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2156243125 is a deficient number, since it is larger than the sum of its proper divisors (538199065).

2156243125 is an frugal number, since it uses more digits than its factorization.

2156243125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3450009 (or 3449994 counting only the distinct ones).

The product of its digits is 14400, while the sum is 31.

The square root of 2156243125 is about 46435.3650249462. The cubic root of 2156243125 is about 1291.9109400425.

Adding to 2156243125 its reverse (5213426512), we get a palindrome (7369669637).

It can be divided in two parts, 21562 and 43125, that multiplied together give a triangular number (929861250 = T₄₃₁₂₄).

The spelling of 2156243125 in words is "two billion, one hundred fifty-six million, two hundred forty-three thousand, one hundred twenty-five".