21378038 has 12 divisors (see below), whose sum is σ = 35247660. Its totient is φ = 9717180.

The previous prime is 21378023. The next prime is 21378041. The reversal of 21378038 is 83087312.

It is a junction number, because it is equal to n+sod(n) for n = 21377995 and 21378013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 43928 + ... + 44411.

It is an arithmetic number, because the mean of its divisors is an integer number (2937305).

Almost surely, 2^21378038 is an apocalyptic number.

21378038 is a deficient number, since it is larger than the sum of its proper divisors (13869622).

21378038 is a wasteful number, since it uses less digits than its factorization.

21378038 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88363 (or 88352 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 21378038 is about 4623.6390430050. The cubic root of 21378038 is about 277.5381026056.

The spelling of 21378038 in words is "twenty-one million, three hundred seventy-eight thousand, thirty-eight".