21457234 has 8 divisors (see below), whose sum is σ = 32206320. Its totient is φ = 10721796.

The previous prime is 21457207. The next prime is 21457253. The reversal of 21457234 is 43275412.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2737 + ... + 7099.

It is an arithmetic number, because the mean of its divisors is an integer number (4025790).

Almost surely, 2^21457234 is an apocalyptic number.

21457234 is a deficient number, since it is larger than the sum of its proper divisors (10749086).

21457234 is a wasteful number, since it uses less digits than its factorization.

21457234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6824.

The product of its digits is 6720, while the sum is 28.

The square root of 21457234 is about 4632.1953758450. The cubic root of 21457234 is about 277.8803981491.

The spelling of 21457234 in words is "twenty-one million, four hundred fifty-seven thousand, two hundred thirty-four".