21049474 has 4 divisors (see below), whose sum is σ = 31574214. Its totient is φ = 10524736.

The previous prime is 21049387. The next prime is 21049493. The reversal of 21049474 is 47494012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16867449 + 4182025 = 4107^2 + 2045^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5262367 + ... + 5262370.

Almost surely, 2^21049474 is an apocalyptic number.

21049474 is a deficient number, since it is larger than the sum of its proper divisors (10524740).

21049474 is a wasteful number, since it uses less digits than its factorization.

21049474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10524739.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 21049474 is about 4587.9705753198. The cubic root of 21049474 is about 276.1089064715.

The spelling of 21049474 in words is "twenty-one million, forty-nine thousand, four hundred seventy-four".