21702073 has 4 divisors (see below), whose sum is σ = 22007808. Its totient is φ = 21396340.

The previous prime is 21702067. The next prime is 21702089. The reversal of 21702073 is 37020712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21702073 - 2¹⁷ = 21571001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21700073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152761 + ... + 152902.

It is an arithmetic number, because the mean of its divisors is an integer number (5501952).

Almost surely, 2^21702073 is an apocalyptic number.

It is an amenable number.

21702073 is a deficient number, since it is larger than the sum of its proper divisors (305735).

21702073 is an equidigital number, since it uses as much as digits as its factorization.

21702073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305734.

The product of its (nonzero) digits is 588, while the sum is 22.

The square root of 21702073 is about 4658.5483790554. The cubic root of 21702073 is about 278.9333268225.

Adding to 21702073 its reverse (37020712), we get a palindrome (58722785).

The spelling of 21702073 in words is "twenty-one million, seven hundred two thousand, seventy-three".