21502238 has 4 divisors (see below), whose sum is σ = 32253360. Its totient is φ = 10751118.

The previous prime is 21502231. The next prime is 21502241. The reversal of 21502238 is 83220512.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21502231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5375558 + ... + 5375561.

It is an arithmetic number, because the mean of its divisors is an integer number (8063340).

Almost surely, 2^21502238 is an apocalyptic number.

21502238 is a deficient number, since it is larger than the sum of its proper divisors (10751122).

21502238 is a wasteful number, since it uses less digits than its factorization.

21502238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10751121.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21502238 is about 4637.0505712144. The cubic root of 21502238 is about 278.0745361963.

The spelling of 21502238 in words is "twenty-one million, five hundred two thousand, two hundred thirty-eight".