21071493 has 12 divisors (see below), whose sum is σ = 30576000. Its totient is φ = 13983336.

The previous prime is 21071489. The next prime is 21071497. The reversal of 21071493 is 39417012.

It is an interprime number because it is at equal distance from previous prime (21071489) and next prime (21071497).

It is not a de Polignac number, because 21071493 - 2² = 21071489 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21071497) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3243 + ... + 7256.

It is an arithmetic number, because the mean of its divisors is an integer number (2548000).

Almost surely, 2^21071493 is an apocalyptic number.

It is an amenable number.

21071493 is a deficient number, since it is larger than the sum of its proper divisors (9504507).

21071493 is a wasteful number, since it uses less digits than its factorization.

21071493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10728 (or 10725 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21071493 is about 4590.3695929631. The cubic root of 21071493 is about 276.2051483594.

It can be divided in two parts, 2107 and 1493, that added together give a square (3600 = 60²).

The spelling of 21071493 in words is "twenty-one million, seventy-one thousand, four hundred ninety-three".