21163155165550 has 48 divisors (see below), whose sum is σ = 39654739612800. Its totient is φ = 8402635445760.

The previous prime is 21163155165527. The next prime is 21163155165577. The reversal of 21163155165550 is 5556155136112.

It is a super-2 number, since 2×21163155165550² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21163155165550.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 71084602 + ... + 71381698.

It is an arithmetic number, because the mean of its divisors is an integer number (826140408600).

Almost surely, 2^{21163155165550} is an apocalyptic number.

21163155165550 is a deficient number, since it is larger than the sum of its proper divisors (18491584447250).

21163155165550 is a wasteful number, since it uses less digits than its factorization.

21163155165550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307645 (or 307640 counting only the distinct ones).

The product of its (nonzero) digits is 675000, while the sum is 46.

The spelling of 21163155165550 in words is "twenty-one trillion, one hundred sixty-three billion, one hundred fifty-five million, one hundred sixty-five thousand, five hundred fifty".