21384450 has 36 divisors (see below), whose sum is σ = 57454098. Its totient is φ = 5702400.

The previous prime is 21384449. The next prime is 21384479. The reversal of 21384450 is 5448312.

21384450 is a `hidden beast` number, since 213 + 8 + 445 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 19421649 + 1962801 = 4407^2 + 1401^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 23311 + ... + 24210.

Almost surely, 2^21384450 is an apocalyptic number.

21384450 is an abundant number, since it is smaller than the sum of its proper divisors (36069648).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21384450 is a wasteful number, since it uses less digits than its factorization.

21384450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47539 (or 47531 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 21384450 is about 4624.3323842475. The cubic root of 21384450 is about 277.5658475344.

The spelling of 21384450 in words is "twenty-one million, three hundred eighty-four thousand, four hundred fifty".