21273855 has 8 divisors (see below), whose sum is σ = 34038192. Its totient is φ = 11346048.

The previous prime is 21273841. The next prime is 21273869. The reversal of 21273855 is 55837212.

It is an interprime number because it is at equal distance from previous prime (21273841) and next prime (21273869).

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

It is not a de Polignac number, because 21273855 - 2⁴ = 21273839 is a prime.

It is a super-2 number, since 2×21273855² = 905153813122050, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 709114 + ... + 709143.

It is an arithmetic number, because the mean of its divisors is an integer number (4254774).

Almost surely, 2^21273855 is an apocalyptic number.

21273855 is a deficient number, since it is larger than the sum of its proper divisors (12764337).

21273855 is a wasteful number, since it uses less digits than its factorization.

21273855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1418265.

The product of its digits is 16800, while the sum is 33.

The square root of 21273855 is about 4612.3589409325. The cubic root of 21273855 is about 277.0865199978.

The spelling of 21273855 in words is "twenty-one million, two hundred seventy-three thousand, eight hundred fifty-five".