21276378 has 16 divisors (see below), whose sum is σ = 47280960. Its totient is φ = 7092108.

The previous prime is 21276377. The next prime is 21276389. The reversal of 21276378 is 87367212.

21276378 is a `hidden beast` number, since 2 + 12 + 7 + 637 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (21276377) 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, 196950 + ... + 197057.

It is an arithmetic number, because the mean of its divisors is an integer number (2955060).

Almost surely, 2^21276378 is an apocalyptic number.

21276378 is an abundant number, since it is smaller than the sum of its proper divisors (26004582).

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

21276378 is a wasteful number, since it uses less digits than its factorization.

21276378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394018 (or 394012 counting only the distinct ones).

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

The square root of 21276378 is about 4612.6324371231. The cubic root of 21276378 is about 277.0974733747.

The spelling of 21276378 in words is "twenty-one million, two hundred seventy-six thousand, three hundred seventy-eight".