21854039 has 8 divisors (see below), whose sum is σ = 22815360. Its totient is φ = 20911440.

The previous prime is 21854011. The next prime is 21854051. The reversal of 21854039 is 93045812.

It is a de Polignac number, because none of the positive numbers 2^k-21854039 is a prime.

It is a super-2 number, since 2×21854039² = 955198041227042, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21853996 and 21854014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21854059) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 245507 + ... + 245595.

It is an arithmetic number, because the mean of its divisors is an integer number (2851920).

Almost surely, 2^21854039 is an apocalyptic number.

21854039 is a deficient number, since it is larger than the sum of its proper divisors (961321).

21854039 is an frugal number, since it uses more digits than its factorization.

21854039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 21854039 is about 4674.8303712541. The cubic root of 21854039 is about 279.5828780628.

The spelling of 21854039 in words is "twenty-one million, eight hundred fifty-four thousand, thirty-nine".