21778059620 has 12 divisors (see below), whose sum is σ = 45733925244. Its totient is φ = 8711223840.

The previous prime is 21778059619. The next prime is 21778059649. The reversal of 21778059620 is 2695087712.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 13202929216 + 8575130404 = 114904^2 + 92602^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 544451471 + ... + 544451510.

It is an arithmetic number, because the mean of its divisors is an integer number (3811160437).

Almost surely, 2^21778059620 is an apocalyptic number.

21778059620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21778059620 is an abundant number, since it is smaller than the sum of its proper divisors (23955865624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21778059620 is a wasteful number, since it uses less digits than its factorization.

21778059620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1088902990 (or 1088902988 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 47.

The spelling of 21778059620 in words is "twenty-one billion, seven hundred seventy-eight million, fifty-nine thousand, six hundred twenty".