21081617182 has 4 divisors (see below), whose sum is σ = 31622425776. Its totient is φ = 10540808590.

The previous prime is 21081617171. The next prime is 21081617197. The reversal of 21081617182 is 28171618012.

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

It is a super-2 number, since 2×21081617182² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5270404294 + ... + 5270404297.

It is an arithmetic number, because the mean of its divisors is an integer number (7905606444).

Almost surely, 2^21081617182 is an apocalyptic number.

21081617182 is a deficient number, since it is larger than the sum of its proper divisors (10540808594).

21081617182 is a wasteful number, since it uses less digits than its factorization.

21081617182 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10540808593.

The product of its (nonzero) digits is 10752, while the sum is 37.

The spelling of 21081617182 in words is "twenty-one billion, eighty-one million, six hundred seventeen thousand, one hundred eighty-two".