1866412538 has 4 divisors (see below), whose sum is σ = 2799618810. Its totient is φ = 933206268.

The previous prime is 1866412531. The next prime is 1866412577. The reversal of 1866412538 is 8352146681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8352146681 = 769 ⋅10861049.

It can be written as a sum of positive squares in only one way, i.e., 1857868609 + 8543929 = 43103^2 + 2923^2 .

It is not an unprimeable number, because it can be changed into a prime (1866412531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 466603133 + ... + 466603136.

Almost surely, 2^1866412538 is an apocalyptic number.

1866412538 is a deficient number, since it is larger than the sum of its proper divisors (933206272).

1866412538 is an equidigital number, since it uses as much as digits as its factorization.

1866412538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933206271.

The product of its digits is 276480, while the sum is 44.

The square root of 1866412538 is about 43201.9969214387. The cubic root of 1866412538 is about 1231.2206222886.

The spelling of 1866412538 in words is "one billion, eight hundred sixty-six million, four hundred twelve thousand, five hundred thirty-eight".