21071151 has 16 divisors (see below), whose sum is σ = 32574720. Its totient is φ = 13436280.

The previous prime is 21071137. The next prime is 21071179. The reversal of 21071151 is 15117012.

It is a happy number.

It is not a de Polignac number, because 21071151 - 2⁵ = 21071119 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21071101) 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 15 ways as a sum of consecutive naturals, for example, 16345 + ... + 17586.

It is an arithmetic number, because the mean of its divisors is an integer number (2035920).

Almost surely, 2^21071151 is an apocalyptic number.

21071151 is a deficient number, since it is larger than the sum of its proper divisors (11503569).

21071151 is a wasteful number, since it uses less digits than its factorization.

21071151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33963 (or 33957 counting only the distinct ones).

The product of its (nonzero) digits is 70, while the sum is 18.

The square root of 21071151 is about 4590.3323409095. The cubic root of 21071151 is about 276.2036540392.

Adding to 21071151 its reverse (15117012), we get a palindrome (36188163).

The spelling of 21071151 in words is "twenty-one million, seventy-one thousand, one hundred fifty-one".