21316361 has 8 divisors (see below), whose sum is σ = 23404224. Its totient is φ = 19253520.

The previous prime is 21316349. The next prime is 21316369. The reversal of 21316361 is 16361312.

It is a happy number.

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

It is not a de Polignac number, because 21316361 - 2⁶ = 21316297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21316369) 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, 4445 + ... + 7898.

It is an arithmetic number, because the mean of its divisors is an integer number (2925528).

Almost surely, 2^21316361 is an apocalyptic number.

It is an amenable number.

21316361 is a deficient number, since it is larger than the sum of its proper divisors (2087863).

21316361 is a wasteful number, since it uses less digits than its factorization.

21316361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12511.

The product of its digits is 648, while the sum is 23.

The square root of 21316361 is about 4616.9644789623. The cubic root of 21316361 is about 277.2709404851.

Adding to 21316361 its reverse (16361312), we get a palindrome (37677673).

It can be divided in two parts, 21316 and 361, that multiplied together give a square (7695076 = 2774²).

The spelling of 21316361 in words is "twenty-one million, three hundred sixteen thousand, three hundred sixty-one".