21073442 has 8 divisors (see below), whose sum is σ = 34041756. Its totient is φ = 9726192.

The previous prime is 21073417. The next prime is 21073447. The reversal of 21073442 is 24437012.

It can be written as a sum of positive squares in 2 ways, for example, as 19088161 + 1985281 = 4369^2 + 1409^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21073447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 405233 + ... + 405284.

Almost surely, 2^21073442 is an apocalyptic number.

21073442 is a deficient number, since it is larger than the sum of its proper divisors (12968314).

21073442 is a wasteful number, since it uses less digits than its factorization.

21073442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810532.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21073442 is about 4590.5818803285. The cubic root of 21073442 is about 276.2136639281.

The spelling of 21073442 in words is "twenty-one million, seventy-three thousand, four hundred forty-two".