21237071 has 2 divisors, whose sum is σ = 21237072. Its totient is φ = 21237070.

The previous prime is 21237043. The next prime is 21237113. The reversal of 21237071 is 17073212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21237071 - 2¹⁴ = 21220687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21237011) 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 as a sum of consecutive naturals, namely, 10618535 + 10618536.

It is an arithmetic number, because the mean of its divisors is an integer number (10618536).

Almost surely, 2^21237071 is an apocalyptic number.

21237071 is a deficient number, since it is larger than the sum of its proper divisors (1).

21237071 is an equidigital number, since it uses as much as digits as its factorization.

21237071 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 21237071 is about 4608.3696683317. The cubic root of 21237071 is about 276.9267271341.

The spelling of 21237071 in words is "twenty-one million, two hundred thirty-seven thousand, seventy-one".