21702617 has 4 divisors (see below), whose sum is σ = 22844880. Its totient is φ = 20560356.

The previous prime is 21702587. The next prime is 21702631. The reversal of 21702617 is 71620712.

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 not a de Polignac number, because 21702617 - 2⁸ = 21702361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21702647) 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, 571103 + ... + 571140.

It is an arithmetic number, because the mean of its divisors is an integer number (5711220).

Almost surely, 2^21702617 is an apocalyptic number.

It is an amenable number.

21702617 is a deficient number, since it is larger than the sum of its proper divisors (1142263).

21702617 is a wasteful number, since it uses less digits than its factorization.

21702617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1142262.

The product of its (nonzero) digits is 1176, while the sum is 26.

The square root of 21702617 is about 4658.6067659763. The cubic root of 21702617 is about 278.9356574518.

The spelling of 21702617 in words is "twenty-one million, seven hundred two thousand, six hundred seventeen".