21492238 has 8 divisors (see below), whose sum is σ = 33278400. Its totient is φ = 10399440.

The previous prime is 21492223. The next prime is 21492239. The reversal of 21492238 is 83229412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21492239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 173263 + ... + 173386.

It is an arithmetic number, because the mean of its divisors is an integer number (4159800).

Almost surely, 2^21492238 is an apocalyptic number.

21492238 is a deficient number, since it is larger than the sum of its proper divisors (11786162).

21492238 is a wasteful number, since it uses less digits than its factorization.

21492238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346682.

The product of its digits is 6912, while the sum is 31.

The square root of 21492238 is about 4635.9721742047. The cubic root of 21492238 is about 278.0314216679.

The spelling of 21492238 in words is "twenty-one million, four hundred ninety-two thousand, two hundred thirty-eight".