21278112 has 48 divisors (see below), whose sum is σ = 57788640. Its totient is φ = 6847232.

The previous prime is 21278111. The next prime is 21278137. The reversal of 21278112 is 21187212.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (21278111) 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, 1038 + ... + 6605.

It is an arithmetic number, because the mean of its divisors is an integer number (1203930).

Almost surely, 2^21278112 is an apocalyptic number.

It is an amenable number.

21278112 is an abundant number, since it is smaller than the sum of its proper divisors (36510528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21278112 is a wasteful number, since it uses less digits than its factorization.

21278112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7685 (or 7677 counting only the distinct ones).

The product of its digits is 448, while the sum is 24.

The square root of 21278112 is about 4612.8203953763. The cubic root of 21278112 is about 277.1050008772.

The spelling of 21278112 in words is "twenty-one million, two hundred seventy-eight thousand, one hundred twelve".