21388414 has 32 divisors (see below), whose sum is σ = 36197280. Its totient is φ = 9418752.

The previous prime is 21388373. The next prime is 21388417. The reversal of 21388414 is 41488312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21388417) 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, 72852 + ... + 73144.

It is an arithmetic number, because the mean of its divisors is an integer number (1131165).

Almost surely, 2^21388414 is an apocalyptic number.

21388414 is a deficient number, since it is larger than the sum of its proper divisors (14808866).

21388414 is a wasteful number, since it uses less digits than its factorization.

21388414 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444.

The product of its digits is 6144, while the sum is 31.

The square root of 21388414 is about 4624.7609667960. The cubic root of 21388414 is about 277.5829971149.

The spelling of 21388414 in words is "twenty-one million, three hundred eighty-eight thousand, four hundred fourteen".