21406019450 has 12 divisors (see below), whose sum is σ = 39815196270. Its totient is φ = 8562407760.

The previous prime is 21406019449. The next prime is 21406019483. The reversal of 21406019450 is 5491060412.

It can be written as a sum of positive squares in 3 ways, for example, as 18566515081 + 2839504369 = 136259^2 + 53287^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214060145 + ... + 214060244.

Almost surely, 2^21406019450 is an apocalyptic number.

21406019450 is a deficient number, since it is larger than the sum of its proper divisors (18409176820).

21406019450 is a wasteful number, since it uses less digits than its factorization.

21406019450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428120401 (or 428120396 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

Adding to 21406019450 its reverse (5491060412), we get a palindrome (26897079862).

The spelling of 21406019450 in words is "twenty-one billion, four hundred six million, nineteen thousand, four hundred fifty".