21078230 has 16 divisors (see below), whose sum is σ = 38049264. Its totient is φ = 8407200.

The previous prime is 21078209. The next prime is 21078257. The reversal of 21078230 is 3287012.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21078196 and 21078205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 905 + ... + 6555.

It is an arithmetic number, because the mean of its divisors is an integer number (2378079).

Almost surely, 2^21078230 is an apocalyptic number.

21078230 is a deficient number, since it is larger than the sum of its proper divisors (16971034).

21078230 is a wasteful number, since it uses less digits than its factorization.

21078230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6031.

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

The square root of 21078230 is about 4591.1033532257. The cubic root of 21078230 is about 276.2345814235.

The spelling of 21078230 in words is "twenty-one million, seventy-eight thousand, two hundred thirty".