21361366 has 16 divisors (see below), whose sum is σ = 34741728. Its totient is φ = 9792000.

The previous prime is 21361303. The next prime is 21361391. The reversal of 21361366 is 66316312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1206 + ... + 6646.

It is an arithmetic number, because the mean of its divisors is an integer number (2171358).

Almost surely, 2^21361366 is an apocalyptic number.

21361366 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21361366 is a deficient number, since it is larger than the sum of its proper divisors (13380362).

21361366 is a wasteful number, since it uses less digits than its factorization.

21361366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5607.

The product of its digits is 3888, while the sum is 28.

The square root of 21361366 is about 4621.8357824570. The cubic root of 21361366 is about 277.4659363539.

Adding to 21361366 its reverse (66316312), we get a palindrome (87677678).

The spelling of 21361366 in words is "twenty-one million, three hundred sixty-one thousand, three hundred sixty-six".