21202139 has 8 divisors (see below), whose sum is σ = 24794880. Its totient is φ = 17750376.

The previous prime is 21202133. The next prime is 21202141. The reversal of 21202139 is 93120212.

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

It is not a de Polignac number, because 21202139 - 2¹⁶ = 21136603 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 21202139.

It is not an unprimeable number, because it can be changed into a prime (21202133) 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, 34919 + ... + 35520.

It is an arithmetic number, because the mean of its divisors is an integer number (3099360).

Almost surely, 2^21202139 is an apocalyptic number.

21202139 is a deficient number, since it is larger than the sum of its proper divisors (3592741).

21202139 is an equidigital number, since it uses as much as digits as its factorization.

21202139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70489.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21202139 is about 4604.5780479866. The cubic root of 21202139 is about 276.7748086141.

The spelling of 21202139 in words is "twenty-one million, two hundred two thousand, one hundred thirty-nine".