21020734 has 8 divisors (see below), whose sum is σ = 36035568. Its totient is φ = 9008880.

The previous prime is 21020719. The next prime is 21020749. The reversal of 21020734 is 43702012.

It is an interprime number because it is at equal distance from previous prime (21020719) and next prime (21020749).

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

It is a congruent number.

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, 750727 + ... + 750754.

It is an arithmetic number, because the mean of its divisors is an integer number (4504446).

Almost surely, 2^21020734 is an apocalyptic number.

21020734 is a deficient number, since it is larger than the sum of its proper divisors (15014834).

21020734 is a wasteful number, since it uses less digits than its factorization.

21020734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1501490.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 21020734 is about 4584.8374016970. The cubic root of 21020734 is about 275.9831870316.

Adding to 21020734 its reverse (43702012), we get a palindrome (64722746).

The spelling of 21020734 in words is "twenty-one million, twenty thousand, seven hundred thirty-four".