21034646 has 4 divisors (see below), whose sum is σ = 31551972. Its totient is φ = 10517322.

The previous prime is 21034613. The next prime is 21034667. The reversal of 21034646 is 64643012.

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

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, 5258660 + ... + 5258663.

It is an arithmetic number, because the mean of its divisors is an integer number (7887993).

Almost surely, 2^21034646 is an apocalyptic number.

21034646 is a deficient number, since it is larger than the sum of its proper divisors (10517326).

21034646 is a wasteful number, since it uses less digits than its factorization.

21034646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10517325.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 21034646 is about 4586.3543256055. The cubic root of 21034646 is about 276.0440575890.

Adding to 21034646 its reverse (64643012), we get a palindrome (85677658).

The spelling of 21034646 in words is "twenty-one million, thirty-four thousand, six hundred forty-six".