21070042 has 8 divisors (see below), whose sum is σ = 36120096. Its totient is φ = 9030012.

The previous prime is 21070033. The next prime is 21070073. The reversal of 21070042 is 24007012.

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

It is a junction number, because it is equal to n+sod(n) for n = 21069998 and 21070025.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 752488 + ... + 752515.

It is an arithmetic number, because the mean of its divisors is an integer number (4515012).

Almost surely, 2^21070042 is an apocalyptic number.

21070042 is a deficient number, since it is larger than the sum of its proper divisors (15050054).

21070042 is a wasteful number, since it uses less digits than its factorization.

21070042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1505012.

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 21070042 is about 4590.2115419662. The cubic root of 21070042 is about 276.1988083108.

Adding to 21070042 its reverse (24007012), we get a palindrome (45077054).

The spelling of 21070042 in words is "twenty-one million, seventy thousand, forty-two".