21670505550 has 72 divisors (see below), whose sum is σ = 58543310280. Its totient is φ = 5746852800.

The previous prime is 21670505513. The next prime is 21670505573. The reversal of 21670505550 is 5550507612.

It is a happy number.

It is a super-2 number, since 2×21670505550² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 51580 + ... + 214479.

Almost surely, 2^21670505550 is an apocalyptic number.

21670505550 is an abundant number, since it is smaller than the sum of its proper divisors (36872804730).

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

21670505550 is a wasteful number, since it uses less digits than its factorization.

21670505550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266258 (or 266250 counting only the distinct ones).

The product of its (nonzero) digits is 52500, while the sum is 36.

The spelling of 21670505550 in words is "twenty-one billion, six hundred seventy million, five hundred five thousand, five hundred fifty".