21292071 has 16 divisors (see below), whose sum is σ = 29445120. Its totient is φ = 13671360.

The previous prime is 21292067. The next prime is 21292091. The reversal of 21292071 is 17029212.

It is not a de Polignac number, because 21292071 - 2² = 21292067 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21292021) 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, 25915 + ... + 26723.

It is an arithmetic number, because the mean of its divisors is an integer number (1840320).

Almost surely, 2^21292071 is an apocalyptic number.

21292071 is a deficient number, since it is larger than the sum of its proper divisors (8153049).

21292071 is a wasteful number, since it uses less digits than its factorization.

21292071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1126.

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 21292071 is about 4614.3332129355. Note that the first 3 decimals coincide. The cubic root of 21292071 is about 277.1655836826.

The spelling of 21292071 in words is "twenty-one million, two hundred ninety-two thousand, seventy-one".