1666376550 has 120 divisors (see below), whose sum is σ = 4902617016. Its totient is φ = 418210560.

The previous prime is 1666376531. The next prime is 1666376599. The reversal of 1666376550 is 556736661.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 1666376496 and 1666376505.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 56749 + ... + 80951.

Almost surely, 2^1666376550 is an apocalyptic number.

1666376550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666376550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2451308508).

1666376550 is an abundant number, since it is smaller than the sum of its proper divisors (3236240466).

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

1666376550 is a wasteful number, since it uses less digits than its factorization.

1666376550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24244 (or 24230 counting only the distinct ones).

The product of its (nonzero) digits is 680400, while the sum is 45.

The square root of 1666376550 is about 40821.2757027509. The cubic root of 1666376550 is about 1185.5623032360.

The spelling of 1666376550 in words is "one billion, six hundred sixty-six million, three hundred seventy-six thousand, five hundred fifty".