21778385002 has 16 divisors (see below), whose sum is σ = 36506562624. Its totient is φ = 9657820000.

The previous prime is 21778384981. The next prime is 21778385011. The reversal of 21778385002 is 20058387712.

It is a self number, because there is not a number n which added to its sum of digits gives 21778385002.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12071374 + ... + 12073177.

It is an arithmetic number, because the mean of its divisors is an integer number (2281660164).

Almost surely, 2^21778385002 is an apocalyptic number.

21778385002 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21778385002 is a deficient number, since it is larger than the sum of its proper divisors (14728177622).

21778385002 is a wasteful number, since it uses less digits than its factorization.

21778385002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24144605.

The product of its (nonzero) digits is 188160, while the sum is 43.

The spelling of 21778385002 in words is "twenty-one billion, seven hundred seventy-eight million, three hundred eighty-five thousand, two".