21451412 has 6 divisors (see below), whose sum is σ = 37539978. Its totient is φ = 10725704.

The previous prime is 21451373. The next prime is 21451427. The reversal of 21451412 is 21415412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 10784656 + 10666756 = 3284^2 + 3266^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2681423 + ... + 2681430.

It is an arithmetic number, because the mean of its divisors is an integer number (6256663).

Almost surely, 2^21451412 is an apocalyptic number.

It is an amenable number.

21451412 is a deficient number, since it is larger than the sum of its proper divisors (16088566).

21451412 is a wasteful number, since it uses less digits than its factorization.

21451412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5362857 (or 5362855 counting only the distinct ones).

The product of its digits is 320, while the sum is 20.

The square root of 21451412 is about 4631.5669054867. The cubic root of 21451412 is about 277.8552634087.

Adding to 21451412 its reverse (21415412), we get a palindrome (42866824).

The spelling of 21451412 in words is "twenty-one million, four hundred fifty-one thousand, four hundred twelve".