21208934 has 4 divisors (see below), whose sum is σ = 31813404. Its totient is φ = 10604466.

The previous prime is 21208927. The next prime is 21208939. The reversal of 21208934 is 43980212.

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 = 21208897 and 21208906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21208939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5302232 + ... + 5302235.

It is an arithmetic number, because the mean of its divisors is an integer number (7953351).

Almost surely, 2^21208934 is an apocalyptic number.

21208934 is a deficient number, since it is larger than the sum of its proper divisors (10604470).

21208934 is a wasteful number, since it uses less digits than its factorization.

21208934 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10604469.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21208934 is about 4605.3158415032. The cubic root of 21208934 is about 276.8043729888.

The spelling of 21208934 in words is "twenty-one million, two hundred eight thousand, nine hundred thirty-four".