21170217356 has 12 divisors (see below), whose sum is σ = 37209663120. Its totient is φ = 10538885040.

The previous prime is 21170217307. The next prime is 21170217371. The reversal of 21170217356 is 65371207112.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11554880 + ... + 11556711.

It is an arithmetic number, because the mean of its divisors is an integer number (3100805260).

Almost surely, 2^21170217356 is an apocalyptic number.

It is an amenable number.

21170217356 is a deficient number, since it is larger than the sum of its proper divisors (16039445764).

21170217356 is a wasteful number, since it uses less digits than its factorization.

21170217356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23111824 (or 23111822 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 35.

The spelling of 21170217356 in words is "twenty-one billion, one hundred seventy million, two hundred seventeen thousand, three hundred fifty-six".