21411538 has 4 divisors (see below), whose sum is σ = 32117310. Its totient is φ = 10705768.

The previous prime is 21411529. The next prime is 21411547. The reversal of 21411538 is 83511412.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21411529) and next prime (21411547).

It can be written as a sum of positive squares in only one way, i.e., 21279769 + 131769 = 4613^2 + 363^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5352883 + ... + 5352886.

Almost surely, 2^21411538 is an apocalyptic number.

21411538 is a deficient number, since it is larger than the sum of its proper divisors (10705772).

21411538 is a wasteful number, since it uses less digits than its factorization.

21411538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10705771.

The product of its digits is 960, while the sum is 25.

The square root of 21411538 is about 4627.2603125392. The cubic root of 21411538 is about 277.6829970086.

The spelling of 21411538 in words is "twenty-one million, four hundred eleven thousand, five hundred thirty-eight".