21421450 has 12 divisors (see below), whose sum is σ = 39843990. Its totient is φ = 8568560.

The previous prime is 21421427. The next prime is 21421451. The reversal of 21421450 is 5412412.

It can be written as a sum of positive squares in 3 ways, for example, as 20007729 + 1413721 = 4473^2 + 1189^2 .

It is not an unprimeable number, because it can be changed into a prime (21421451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214165 + ... + 214264.

Almost surely, 2^21421450 is an apocalyptic number.

21421450 is a deficient number, since it is larger than the sum of its proper divisors (18422540).

21421450 is a wasteful number, since it uses less digits than its factorization.

21421450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428441 (or 428436 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 21421450 is about 4628.3312327447. The cubic root of 21421450 is about 277.7258394745.

Adding to 21421450 its reverse (5412412), we get a palindrome (26833862).

The spelling of 21421450 in words is "twenty-one million, four hundred twenty-one thousand, four hundred fifty".