21702661867 has 4 divisors (see below), whose sum is σ = 21703868856. Its totient is φ = 21701454880.

The previous prime is 21702661847. The next prime is 21702661889. The reversal of 21702661867 is 76816620712.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21702661867 - 2¹¹ = 21702659819 is a prime.

It is a super-2 number, since 2×21702661867² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21702661807) 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, 576109 + ... + 612622.

It is an arithmetic number, because the mean of its divisors is an integer number (5425967214).

Almost surely, 2^21702661867 is an apocalyptic number.

21702661867 is a deficient number, since it is larger than the sum of its proper divisors (1206989).

21702661867 is a wasteful number, since it uses less digits than its factorization.

21702661867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1206988.

The product of its (nonzero) digits is 338688, while the sum is 46.

The spelling of 21702661867 in words is "twenty-one billion, seven hundred two million, six hundred sixty-one thousand, eight hundred sixty-seven".