21366371 has 8 divisors (see below), whose sum is σ = 23571744. Its totient is φ = 19241280.

The previous prime is 21366343. The next prime is 21366377. The reversal of 21366371 is 17366312.

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

It is a cyclic number.

It is not a de Polignac number, because 21366371 - 2¹⁰ = 21365347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21366377) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19511 + ... + 20576.

It is an arithmetic number, because the mean of its divisors is an integer number (2946468).

Almost surely, 2^21366371 is an apocalyptic number.

21366371 is a deficient number, since it is larger than the sum of its proper divisors (2205373).

21366371 is a wasteful number, since it uses less digits than its factorization.

21366371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40141.

The product of its digits is 4536, while the sum is 29.

The square root of 21366371 is about 4622.3772022629. The cubic root of 21366371 is about 277.4876048896.

The spelling of 21366371 in words is "twenty-one million, three hundred sixty-six thousand, three hundred seventy-one".