21278043 has 12 divisors (see below), whose sum is σ = 32352840. Its totient is φ = 13438656.

The previous prime is 21278041. The next prime is 21278063. The reversal of 21278043 is 34087212.

It is not a de Polignac number, because 21278043 - 2¹ = 21278041 is a prime.

It is a super-2 number, since 2×21278043² = 905510227819698, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21277998 and 21278016.

It is not an unprimeable number, because it can be changed into a prime (21278041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62046 + ... + 62387.

It is an arithmetic number, because the mean of its divisors is an integer number (2696070).

Almost surely, 2^21278043 is an apocalyptic number.

21278043 is a deficient number, since it is larger than the sum of its proper divisors (11074797).

21278043 is a wasteful number, since it uses less digits than its factorization.

21278043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124458 (or 124455 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21278043 is about 4612.8129162150. The cubic root of 21278043 is about 277.1047013477.

The spelling of 21278043 in words is "twenty-one million, two hundred seventy-eight thousand, forty-three".