21121412 has 24 divisors (see below), whose sum is σ = 42149016. Its totient is φ = 9174528.

The previous prime is 21121411. The next prime is 21121417. The reversal of 21121412 is 21412112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6635776 + 14485636 = 2576^2 + 3806^2 .

It is a super-2 number, since 2×21121412² = 892228089747488, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21121411) 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, 11063 + ... + 12830.

It is an arithmetic number, because the mean of its divisors is an integer number (1756209).

Almost surely, 2^21121412 is an apocalyptic number.

It is an amenable number.

21121412 is a deficient number, since it is larger than the sum of its proper divisors (21027604).

21121412 is a wasteful number, since it uses less digits than its factorization.

21121412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23927 (or 23925 counting only the distinct ones).

The product of its digits is 32, while the sum is 14.

The square root of 21121412 is about 4595.8037381942. The cubic root of 21121412 is about 276.4230891122.

Adding to 21121412 its reverse (21412112), we get a palindrome (42533524).

The spelling of 21121412 in words is "twenty-one million, one hundred twenty-one thousand, four hundred twelve".