21361081 has 8 divisors (see below), whose sum is σ = 25254720. Its totient is φ = 17677968.

The previous prime is 21361079. The next prime is 21361091. The reversal of 21361081 is 18016312.

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

It is not a de Polignac number, because 21361081 - 2¹ = 21361079 is a prime.

It is a super-2 number, since 2×21361081² = 912591562977122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21361001) 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, 52411 + ... + 52816.

It is an arithmetic number, because the mean of its divisors is an integer number (3156840).

Almost surely, 2^21361081 is an apocalyptic number.

It is an amenable number.

21361081 is a deficient number, since it is larger than the sum of its proper divisors (3893639).

21361081 is a wasteful number, since it uses less digits than its factorization.

21361081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105263.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 21361081 is about 4621.8049504496. The cubic root of 21361081 is about 277.4647023794.

Adding to 21361081 its reverse (18016312), we get a palindrome (39377393).

The spelling of 21361081 in words is "twenty-one million, three hundred sixty-one thousand, eighty-one".