21871283 has 4 divisors (see below), whose sum is σ = 24995760. Its totient is φ = 18746808.

The previous prime is 21871273. The next prime is 21871303. The reversal of 21871283 is 38217812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21871283 is a prime.

It is a super-3 number, since 3×21871283³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21871243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1562228 + ... + 1562241.

It is an arithmetic number, because the mean of its divisors is an integer number (6248940).

Almost surely, 2^21871283 is an apocalyptic number.

21871283 is a deficient number, since it is larger than the sum of its proper divisors (3124477).

21871283 is an equidigital number, since it uses as much as digits as its factorization.

21871283 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3124476.

The product of its digits is 5376, while the sum is 32.

The square root of 21871283 is about 4676.6743525715. The cubic root of 21871283 is about 279.6563939876.

The spelling of 21871283 in words is "twenty-one million, eight hundred seventy-one thousand, two hundred eighty-three".