21301378 has 12 divisors (see below), whose sum is σ = 37168902. Its totient is φ = 9129120.

The previous prime is 21301363. The next prime is 21301403. The reversal of 21301378 is 87310312.

It can be written as a sum of positive squares in only one way, i.e., 21279769 + 21609 = 4613^2 + 147^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 108583 + ... + 108778.

Almost surely, 2^21301378 is an apocalyptic number.

21301378 is a deficient number, since it is larger than the sum of its proper divisors (15867524).

21301378 is a wasteful number, since it uses less digits than its factorization.

21301378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217377 (or 217370 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 21301378 is about 4615.3415908251. The cubic root of 21301378 is about 277.2059618484.

The spelling of 21301378 in words is "twenty-one million, three hundred one thousand, three hundred seventy-eight".