21871308 has 24 divisors (see below), whose sum is σ = 51681280. Its totient is φ = 7197840.

The previous prime is 21871303. The next prime is 21871319. The reversal of 21871308 is 80317812.

It is a happy number.

It is a super-2 number, since 2×21871308² = 956708227261728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21871303) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10588 + ... + 12483.

Almost surely, 2^21871308 is an apocalyptic number.

It is an amenable number.

21871308 is an abundant number, since it is smaller than the sum of its proper divisors (29809972).

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

21871308 is a wasteful number, since it uses less digits than its factorization.

21871308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23157 (or 23155 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 21871308 is about 4676.6770254102. The cubic root of 21871308 is about 279.6565005415.

The spelling of 21871308 in words is "twenty-one million, eight hundred seventy-one thousand, three hundred eight".