21870355550 has 12 divisors (see below), whose sum is σ = 40678861416. Its totient is φ = 8748142200.

The previous prime is 21870355541. The next prime is 21870355601. The reversal of 21870355550 is 5555307812.

It is a junction number, because it is equal to n+sod(n) for n = 21870355498 and 21870355507.

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 5 ways as a sum of consecutive naturals, for example, 218703506 + ... + 218703605.

It is an arithmetic number, because the mean of its divisors is an integer number (3389905118).

Almost surely, 2^21870355550 is an apocalyptic number.

21870355550 is a deficient number, since it is larger than the sum of its proper divisors (18808505866).

21870355550 is a wasteful number, since it uses less digits than its factorization.

21870355550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437407123 (or 437407118 counting only the distinct ones).

The product of its (nonzero) digits is 210000, while the sum is 41.

The spelling of 21870355550 in words is "twenty-one billion, eight hundred seventy million, three hundred fifty-five thousand, five hundred fifty".