21670046 has 4 divisors (see below), whose sum is σ = 32505072. Its totient is φ = 10835022.

The previous prime is 21670037. The next prime is 21670063. The reversal of 21670046 is 64007612.

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

It is a junction number, because it is equal to n+sod(n) for n = 21669997 and 21670024.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5417510 + ... + 5417513.

It is an arithmetic number, because the mean of its divisors is an integer number (8126268).

Almost surely, 2^21670046 is an apocalyptic number.

21670046 is a deficient number, since it is larger than the sum of its proper divisors (10835026).

21670046 is a wasteful number, since it uses less digits than its factorization.

21670046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10835025.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 21670046 is about 4655.1096657329. The cubic root of 21670046 is about 278.7960466070.

Adding to 21670046 its reverse (64007612), we get a palindrome (85677658).

The spelling of 21670046 in words is "twenty-one million, six hundred seventy thousand, forty-six".