21234188 has 6 divisors (see below), whose sum is σ = 37159836. Its totient is φ = 10617092.

The previous prime is 21234151. The next prime is 21234203. The reversal of 21234188 is 88143212.

It is a self number, because there is not a number n which added to its sum of digits gives 21234188.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2654270 + ... + 2654277.

It is an arithmetic number, because the mean of its divisors is an integer number (6193306).

Almost surely, 2^21234188 is an apocalyptic number.

It is an amenable number.

21234188 is a deficient number, since it is larger than the sum of its proper divisors (15925648).

21234188 is a wasteful number, since it uses less digits than its factorization.

21234188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5308551 (or 5308549 counting only the distinct ones).

The product of its digits is 3072, while the sum is 29.

The square root of 21234188 is about 4608.0568572881. The cubic root of 21234188 is about 276.9141953388.

The spelling of 21234188 in words is "twenty-one million, two hundred thirty-four thousand, one hundred eighty-eight".