21711234 has 16 divisors (see below), whose sum is σ = 43500672. Its totient is φ = 7224048.

The previous prime is 21711229. The next prime is 21711269. The reversal of 21711234 is 43211712.

It is a self number, because there is not a number n which added to its sum of digits gives 21711234.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 727 + ... + 6629.

It is an arithmetic number, because the mean of its divisors is an integer number (2718792).

Almost surely, 2^21711234 is an apocalyptic number.

21711234 is an abundant number, since it is smaller than the sum of its proper divisors (21789438).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21711234 is a wasteful number, since it uses less digits than its factorization.

21711234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6521.

The product of its digits is 336, while the sum is 21.

The square root of 21711234 is about 4659.5315215159. The cubic root of 21711234 is about 278.9725695980.

Adding to 21711234 its reverse (43211712), we get a palindrome (64922946).

It can be divided in two parts, 21711 and 234, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21711234 in words is "twenty-one million, seven hundred eleven thousand, two hundred thirty-four".