2166643550 has 12 divisors (see below), whose sum is σ = 4029957096. Its totient is φ = 866657400.

The previous prime is 2166643547. The next prime is 2166643559. The reversal of 2166643550 is 553466612.

It is a happy number.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2166643559) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21666386 + ... + 21666485.

It is an arithmetic number, because the mean of its divisors is an integer number (335829758).

Almost surely, 2^2166643550 is an apocalyptic number.

2166643550 is a deficient number, since it is larger than the sum of its proper divisors (1863313546).

2166643550 is a wasteful number, since it uses less digits than its factorization.

2166643550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43332883 (or 43332878 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 38.

The square root of 2166643550 is about 46547.2184990682. The cubic root of 2166643550 is about 1293.9847441360.

The spelling of 2166643550 in words is "two billion, one hundred sixty-six million, six hundred forty-three thousand, five hundred fifty".