21023834 has 16 divisors (see below), whose sum is σ = 34234368. Its totient is φ = 9625392.

The previous prime is 21023831. The next prime is 21023837. The reversal of 21023834 is 43832012.

It is an interprime number because it is at equal distance from previous prime (21023831) and next prime (21023837).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21023831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119 + ... + 6485.

It is an arithmetic number, because the mean of its divisors is an integer number (2139648).

Almost surely, 2^21023834 is an apocalyptic number.

21023834 is a deficient number, since it is larger than the sum of its proper divisors (13210534).

21023834 is a wasteful number, since it uses less digits than its factorization.

21023834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6509.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 21023834 is about 4585.1754601106. The cubic root of 21023834 is about 275.9967530949.

Adding to 21023834 its reverse (43832012), we get a palindrome (64855846).

The spelling of 21023834 in words is "twenty-one million, twenty-three thousand, eight hundred thirty-four".