21388274 has 8 divisors (see below), whose sum is σ = 32160240. Its totient is φ = 10668196.

The previous prime is 21388271. The next prime is 21388277. The reversal of 21388274 is 47288312.

It is an interprime number because it is at equal distance from previous prime (21388271) and next prime (21388277).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21388271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11924 + ... + 13599.

It is an arithmetic number, because the mean of its divisors is an integer number (4020030).

Almost surely, 2^21388274 is an apocalyptic number.

21388274 is a deficient number, since it is larger than the sum of its proper divisors (10771966).

21388274 is a wasteful number, since it uses less digits than its factorization.

21388274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25944.

The product of its digits is 21504, while the sum is 35.

The square root of 21388274 is about 4624.7458308538. The cubic root of 21388274 is about 277.5823914645.

The spelling of 21388274 in words is "twenty-one million, three hundred eighty-eight thousand, two hundred seventy-four".