21160381 has 4 divisors (see below), whose sum is σ = 23084064. Its totient is φ = 19236700.

The previous prime is 21160379. The next prime is 21160397. The reversal of 21160381 is 18306112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21160381 - 2¹ = 21160379 is a prime.

It is a super-2 number, since 2×21160381² = 895523448130322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21160301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 961825 + ... + 961846.

It is an arithmetic number, because the mean of its divisors is an integer number (5771016).

Almost surely, 2^21160381 is an apocalyptic number.

It is an amenable number.

21160381 is a deficient number, since it is larger than the sum of its proper divisors (1923683).

21160381 is a wasteful number, since it uses less digits than its factorization.

21160381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1923682.

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

The square root of 21160381 is about 4600.0414128571. The cubic root of 21160381 is about 276.5929848465.

Adding to 21160381 its reverse (18306112), we get a palindrome (39466493).

The spelling of 21160381 in words is "twenty-one million, one hundred sixty thousand, three hundred eighty-one".