21355555106 has 8 divisors (see below), whose sum is σ = 32637735324. Its totient is φ = 10476310000.

The previous prime is 21355555103. The next prime is 21355555139. The reversal of 21355555106 is 60155555312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21302862025 + 52693081 = 145955^2 + 7259^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21355555106.

It is not an unprimeable number, because it can be changed into a prime (21355555103) 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, 100733645 + ... + 100733856.

Almost surely, 2^21355555106 is an apocalyptic number.

21355555106 is a deficient number, since it is larger than the sum of its proper divisors (11282180218).

21355555106 is a wasteful number, since it uses less digits than its factorization.

21355555106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201467556.

The product of its (nonzero) digits is 112500, while the sum is 38.

The spelling of 21355555106 in words is "twenty-one billion, three hundred fifty-five million, five hundred fifty-five thousand, one hundred six".