21301971 has 4 divisors (see below), whose sum is σ = 28402632. Its totient is φ = 14201312.

The previous prime is 21301967. The next prime is 21301997. The reversal of 21301971 is 17910312.

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

It is a cyclic number.

It is not a de Polignac number, because 21301971 - 2² = 21301967 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21301471) 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 3 ways as a sum of consecutive naturals, for example, 3550326 + ... + 3550331.

It is an arithmetic number, because the mean of its divisors is an integer number (7100658).

Almost surely, 2^21301971 is an apocalyptic number.

21301971 is a deficient number, since it is larger than the sum of its proper divisors (7100661).

21301971 is an equidigital number, since it uses as much as digits as its factorization.

21301971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7100660.

The product of its (nonzero) digits is 378, while the sum is 24.

The square root of 21301971 is about 4615.4058326435. The cubic root of 21301971 is about 277.2085341642.

The spelling of 21301971 in words is "twenty-one million, three hundred one thousand, nine hundred seventy-one".