21026734 has 4 divisors (see below), whose sum is σ = 31540104. Its totient is φ = 10513366.

The previous prime is 21026717. The next prime is 21026741. The reversal of 21026734 is 43762012.

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 = 21026699 and 21026708.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5256682 + ... + 5256685.

It is an arithmetic number, because the mean of its divisors is an integer number (7885026).

Almost surely, 2^21026734 is an apocalyptic number.

21026734 is a deficient number, since it is larger than the sum of its proper divisors (10513370).

21026734 is a wasteful number, since it uses less digits than its factorization.

21026734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10513369.

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 21026734 is about 4585.4916857410. The cubic root of 21026734 is about 276.0094427211.

Adding to 21026734 its reverse (43762012), we get a palindrome (64788746).

It can be divided in two parts, 2102 and 6734, that added together give a square (8836 = 94²).

The spelling of 21026734 in words is "twenty-one million, twenty-six thousand, seven hundred thirty-four".