21854438 has 4 divisors (see below), whose sum is σ = 32781660. Its totient is φ = 10927218.

The previous prime is 21854431. The next prime is 21854461. The reversal of 21854438 is 83445812.

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 = 21854398 and 21854407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21854431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5463608 + ... + 5463611.

It is an arithmetic number, because the mean of its divisors is an integer number (8195415).

Almost surely, 2^21854438 is an apocalyptic number.

21854438 is a deficient number, since it is larger than the sum of its proper divisors (10927222).

21854438 is a wasteful number, since it uses less digits than its factorization.

21854438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10927221.

The product of its digits is 30720, while the sum is 35.

The square root of 21854438 is about 4674.8730464046. The cubic root of 21854438 is about 279.5845795468.

The spelling of 21854438 in words is "twenty-one million, eight hundred fifty-four thousand, four hundred thirty-eight".