21382481 has 8 divisors (see below), whose sum is σ = 23167584. Its totient is φ = 19656000.

The previous prime is 21382463. The next prime is 21382499. The reversal of 21382481 is 18428312.

It is an interprime number because it is at equal distance from previous prime (21382463) and next prime (21382499).

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

It is a cyclic number.

It is not a de Polignac number, because 21382481 - 2¹⁰ = 21381457 is a prime.

It is a super-2 number, since 2×21382481² = 914420987430722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21382441) 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, 13895 + ... + 15356.

It is an arithmetic number, because the mean of its divisors is an integer number (2895948).

Almost surely, 2^21382481 is an apocalyptic number.

It is an amenable number.

21382481 is a deficient number, since it is larger than the sum of its proper divisors (1785103).

21382481 is a wasteful number, since it uses less digits than its factorization.

21382481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29311.

The product of its digits is 3072, while the sum is 29.

The square root of 21382481 is about 4624.1194837504. The cubic root of 21382481 is about 277.5573281986.

The spelling of 21382481 in words is "twenty-one million, three hundred eighty-two thousand, four hundred eighty-one".