21273867 has 16 divisors (see below), whose sum is σ = 31600000. Its totient is φ = 14145192.

The previous prime is 21273841. The next prime is 21273869. The reversal of 21273867 is 76837212.

It is not a de Polignac number, because 21273867 - 2⁶ = 21273803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21273869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12684 + ... + 14262.

It is an arithmetic number, because the mean of its divisors is an integer number (1975000).

Almost surely, 2^21273867 is an apocalyptic number.

21273867 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21273867 is a deficient number, since it is larger than the sum of its proper divisors (10326133).

21273867 is a wasteful number, since it uses less digits than its factorization.

21273867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2087 (or 2081 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 21273867 is about 4612.3602417851. The cubic root of 21273867 is about 277.0865720967.

The spelling of 21273867 in words is "twenty-one million, two hundred seventy-three thousand, eight hundred sixty-seven".