283138921 has 4 divisors (see below), whose sum is σ = 304918852. Its totient is φ = 261358992.

The previous prime is 283138871. The next prime is 283138939. The reversal of 283138921 is 129831382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129831382 = 2 ⋅64915691.

It can be written as a sum of positive squares in 2 ways, for example, as 91011600 + 192127321 = 9540^2 + 13861^2 .

It is a cyclic number.

It is not a de Polignac number, because 283138921 - 2⁹ = 283138409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (283138721) 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 3 ways as a sum of consecutive naturals, for example, 10889946 + ... + 10889971.

It is an arithmetic number, because the mean of its divisors is an integer number (76229713).

Almost surely, 2^283138921 is an apocalyptic number.

It is an amenable number.

283138921 is a deficient number, since it is larger than the sum of its proper divisors (21779931).

283138921 is a wasteful number, since it uses less digits than its factorization.

283138921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21779930.

The product of its digits is 20736, while the sum is 37.

The square root of 283138921 is about 16826.7323328090. The cubic root of 283138921 is about 656.6488543644.

The spelling of 283138921 in words is "two hundred eighty-three million, one hundred thirty-eight thousand, nine hundred twenty-one".