21239412 has 24 divisors (see below), whose sum is σ = 49787136. Its totient is φ = 7047168.

The previous prime is 21239381. The next prime is 21239429. The reversal of 21239412 is 21493212.

It is a super-2 number, since 2×21239412² = 902225244211488, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1293 + ... + 6644.

It is an arithmetic number, because the mean of its divisors is an integer number (2074464).

Almost surely, 2^21239412 is an apocalyptic number.

It is an amenable number.

21239412 is an abundant number, since it is smaller than the sum of its proper divisors (28547724).

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

21239412 is a wasteful number, since it uses less digits than its factorization.

21239412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8167 (or 8165 counting only the distinct ones).

The product of its digits is 864, while the sum is 24.

The square root of 21239412 is about 4608.6236557133. The cubic root of 21239412 is about 276.9369021350.

The spelling of 21239412 in words is "twenty-one million, two hundred thirty-nine thousand, four hundred twelve".