21331412 has 6 divisors (see below), whose sum is σ = 37329978. Its totient is φ = 10665704.

The previous prime is 21331399. The next prime is 21331451. The reversal of 21331412 is 21413312.

It can be written as a sum of positive squares in only one way, i.e., 21104836 + 226576 = 4594^2 + 476^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2666423 + ... + 2666430.

It is an arithmetic number, because the mean of its divisors is an integer number (6221663).

Almost surely, 2^21331412 is an apocalyptic number.

It is an amenable number.

21331412 is a deficient number, since it is larger than the sum of its proper divisors (15998566).

21331412 is a wasteful number, since it uses less digits than its factorization.

21331412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5332857 (or 5332855 counting only the distinct ones).

The product of its digits is 144, while the sum is 17.

The square root of 21331412 is about 4618.5941583993. The cubic root of 21331412 is about 277.3361833770.

Adding to 21331412 its reverse (21413312), we get a palindrome (42744724).

The spelling of 21331412 in words is "twenty-one million, three hundred thirty-one thousand, four hundred twelve".