21020378 has 8 divisors (see below), whose sum is σ = 32263968. Its totient is φ = 10265724.

The previous prime is 21020369. The next prime is 21020407. The reversal of 21020378 is 87302012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 122126 + ... + 122297.

It is an arithmetic number, because the mean of its divisors is an integer number (4032996).

Almost surely, 2^21020378 is an apocalyptic number.

21020378 is a deficient number, since it is larger than the sum of its proper divisors (11243590).

21020378 is a wasteful number, since it uses less digits than its factorization.

21020378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244468.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21020378 is about 4584.7985779094. The cubic root of 21020378 is about 275.9816290370.

The spelling of 21020378 in words is "twenty-one million, twenty thousand, three hundred seventy-eight".