21445412 has 6 divisors (see below), whose sum is σ = 37529478. Its totient is φ = 10722704.

The previous prime is 21445409. The next prime is 21445441. The reversal of 21445412 is 21454412.

It can be written as a sum of positive squares in only one way, i.e., 15413476 + 6031936 = 3926^2 + 2456^2 .

It is a super-3 number, since 3×21445412³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2680673 + ... + 2680680.

It is an arithmetic number, because the mean of its divisors is an integer number (6254913).

Almost surely, 2^21445412 is an apocalyptic number.

It is an amenable number.

21445412 is a deficient number, since it is larger than the sum of its proper divisors (16084066).

21445412 is a wasteful number, since it uses less digits than its factorization.

21445412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5361357 (or 5361355 counting only the distinct ones).

The product of its digits is 1280, while the sum is 23.

The square root of 21445412 is about 4630.9191312309. The cubic root of 21445412 is about 277.8293554477.

Adding to 21445412 its reverse (21454412), we get a palindrome (42899824).

The spelling of 21445412 in words is "twenty-one million, four hundred forty-five thousand, four hundred twelve".