21142371 has 4 divisors (see below), whose sum is σ = 28189832. Its totient is φ = 14094912.

The previous prime is 21142361. The next prime is 21142379. The reversal of 21142371 is 17324112.

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

It is not a de Polignac number, because 21142371 - 2⁷ = 21142243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21142379) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3523726 + ... + 3523731.

It is an arithmetic number, because the mean of its divisors is an integer number (7047458).

Almost surely, 2^21142371 is an apocalyptic number.

21142371 is a deficient number, since it is larger than the sum of its proper divisors (7047461).

21142371 is an equidigital number, since it uses as much as digits as its factorization.

21142371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7047460.

The product of its digits is 336, while the sum is 21.

The square root of 21142371 is about 4598.0834050722. The cubic root of 21142371 is about 276.5144914017.

Adding to 21142371 its reverse (17324112), we get a palindrome (38466483).

The spelling of 21142371 in words is "twenty-one million, one hundred forty-two thousand, three hundred seventy-one".