21382641 has 24 divisors (see below), whose sum is σ = 35503104. Its totient is φ = 12147840.

The previous prime is 21382597. The next prime is 21382661. The reversal of 21382641 is 14628312.

21382641 is a `hidden beast` number, since 2 + 13 + 8 + 2 + 641 = 666.

It is not a de Polignac number, because 21382641 - 2⁹ = 21382129 is a prime.

It is a super-2 number, since 2×21382641² = 914434672269762, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21382661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11145 + ... + 12921.

It is an arithmetic number, because the mean of its divisors is an integer number (1479296).

Almost surely, 2^21382641 is an apocalyptic number.

21382641 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21382641 is a deficient number, since it is larger than the sum of its proper divisors (14120463).

21382641 is a wasteful number, since it uses less digits than its factorization.

21382641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1981 (or 1978 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 21382641 is about 4624.1367843090. The cubic root of 21382641 is about 277.5580204953.

The spelling of 21382641 in words is "twenty-one million, three hundred eighty-two thousand, six hundred forty-one".