21878334 has 12 divisors (see below), whose sum is σ = 47403096. Its totient is φ = 7292772.

The previous prime is 21878327. The next prime is 21878341. The reversal of 21878334 is 43387812.

It is an interprime number because it is at equal distance from previous prime (21878327) and next prime (21878341).

It is a super-2 number, since 2×21878334² = 957322997231112, which contains 22 as substring.

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, 607714 + ... + 607749.

It is an arithmetic number, because the mean of its divisors is an integer number (3950258).

Almost surely, 2^21878334 is an apocalyptic number.

21878334 is an abundant number, since it is smaller than the sum of its proper divisors (25524762).

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

21878334 is a wasteful number, since it uses less digits than its factorization.

21878334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1215471 (or 1215468 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 21878334 is about 4677.4281394801. The cubic root of 21878334 is about 279.6864432136.

The spelling of 21878334 in words is "twenty-one million, eight hundred seventy-eight thousand, three hundred thirty-four".