21369378 has 32 divisors (see below), whose sum is σ = 43623360. Its totient is φ = 6977600.

The previous prime is 21369377. The next prime is 21369379. The reversal of 21369378 is 87396312.

It is an interprime number because it is at equal distance from previous prime (21369377) and next prime (21369379).

It is a super-2 number, since 2×21369378² = 913300632213768, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21369371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108376 + ... + 108572.

It is an arithmetic number, because the mean of its divisors is an integer number (1363230).

Almost surely, 2^21369378 is an apocalyptic number.

21369378 is an abundant number, since it is smaller than the sum of its proper divisors (22253982).

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

21369378 is a wasteful number, since it uses less digits than its factorization.

21369378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 482.

The product of its digits is 54432, while the sum is 39.

The square root of 21369378 is about 4622.7024563560. The cubic root of 21369378 is about 277.5006217014.

The spelling of 21369378 in words is "twenty-one million, three hundred sixty-nine thousand, three hundred seventy-eight".