21340012 has 6 divisors (see below), whose sum is σ = 37345028. Its totient is φ = 10670004.

The previous prime is 21340003. The next prime is 21340019. The reversal of 21340012 is 21004312.

It is a super-2 number, since 2×21340012² = 910792224320288, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21339974 and 21340001.

It is not an unprimeable number, because it can be changed into a prime (21340019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2667498 + ... + 2667505.

Almost surely, 2^21340012 is an apocalyptic number.

It is an amenable number.

21340012 is a deficient number, since it is larger than the sum of its proper divisors (16005016).

21340012 is a wasteful number, since it uses less digits than its factorization.

21340012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5335007 (or 5335005 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21340012 is about 4619.5250838154. The cubic root of 21340012 is about 277.3734487757.

Adding to 21340012 its reverse (21004312), we get a palindrome (42344324).

The spelling of 21340012 in words is "twenty-one million, three hundred forty thousand, twelve".