21202393 has 4 divisors (see below), whose sum is σ = 21933540. Its totient is φ = 20471248.

The previous prime is 21202387. The next prime is 21202399. The reversal of 21202393 is 39320212.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21202387) and next prime (21202399).

It can be written as a sum of positive squares in 2 ways, for example, as 13601344 + 7601049 = 3688^2 + 2757^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202393 - 2¹⁷ = 21071321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21202399) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 365530 + ... + 365587.

It is an arithmetic number, because the mean of its divisors is an integer number (5483385).

Almost surely, 2^21202393 is an apocalyptic number.

It is an amenable number.

21202393 is a deficient number, since it is larger than the sum of its proper divisors (731147).

21202393 is an equidigital number, since it uses as much as digits as its factorization.

21202393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 731146.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21202393 is about 4604.6056291500. The cubic root of 21202393 is about 276.7759138566.

The spelling of 21202393 in words is "twenty-one million, two hundred two thousand, three hundred ninety-three".