21816741 has 8 divisors (see below), whose sum is σ = 29523424. Its totient is φ = 14327280.

The previous prime is 21816733. The next prime is 21816749. The reversal of 21816741 is 14761812.

It is an interprime number because it is at equal distance from previous prime (21816733) and next prime (21816749).

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

It is not a de Polignac number, because 21816741 - 2³ = 21816733 is a prime.

It is a super-2 number, since 2×21816741² = 951940375722162, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21816699 and 21816708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21816749) 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 7 ways as a sum of consecutive naturals, for example, 54070 + ... + 54471.

It is an arithmetic number, because the mean of its divisors is an integer number (3690428).

Almost surely, 2^21816741 is an apocalyptic number.

It is an amenable number.

21816741 is a deficient number, since it is larger than the sum of its proper divisors (7706683).

21816741 is a wasteful number, since it uses less digits than its factorization.

21816741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108611.

The product of its digits is 2688, while the sum is 30.

The square root of 21816741 is about 4670.8394320507. The cubic root of 21816741 is about 279.4237340225.

The spelling of 21816741 in words is "twenty-one million, eight hundred sixteen thousand, seven hundred forty-one".