21374521 has 8 divisors (see below), whose sum is σ = 25490304. Its totient is φ = 17524320.

The previous prime is 21374513. The next prime is 21374543. The reversal of 21374521 is 12547312.

It is a happy number.

21374521 is nontrivially palindromic in base 15.

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 21374521 - 2³ = 21374513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21374021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66220 + ... + 66541.

It is an arithmetic number, because the mean of its divisors is an integer number (3186288).

Almost surely, 2^21374521 is an apocalyptic number.

It is an amenable number.

21374521 is a deficient number, since it is larger than the sum of its proper divisors (4115783).

21374521 is a wasteful number, since it uses less digits than its factorization.

21374521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132791.

The product of its digits is 1680, while the sum is 25.

The square root of 21374521 is about 4623.2586992294. The cubic root of 21374521 is about 277.5228820782.

The spelling of 21374521 in words is "twenty-one million, three hundred seventy-four thousand, five hundred twenty-one".