21397053 has 8 divisors (see below), whose sum is σ = 28955488. Its totient is φ = 14051664.

The previous prime is 21397043. The next prime is 21397069. The reversal of 21397053 is 35079312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21397053 - 2¹⁰ = 21396029 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21397053.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21397043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53026 + ... + 53427.

It is an arithmetic number, because the mean of its divisors is an integer number (3619436).

Almost surely, 2^21397053 is an apocalyptic number.

It is an amenable number.

21397053 is a deficient number, since it is larger than the sum of its proper divisors (7558435).

21397053 is a wasteful number, since it uses less digits than its factorization.

21397053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106523.

The product of its (nonzero) digits is 5670, while the sum is 30.

The square root of 21397053 is about 4625.6948667200. The cubic root of 21397053 is about 277.6203649584.

The spelling of 21397053 in words is "twenty-one million, three hundred ninety-seven thousand, fifty-three".