66669750 has 256 divisors, whose sum is σ = 226437120. Its totient is φ = 14169600.

The previous prime is 66669739. The next prime is 66669751. The reversal of 66669750 is 5796666.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66669696 and 66669705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66669751) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 803209 + ... + 803291.

It is an arithmetic number, because the mean of its divisors is an integer number (884520).

Almost surely, 2^66669750 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66669750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113218560).

66669750 is an abundant number, since it is smaller than the sum of its proper divisors (159767370).

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

66669750 is a wasteful number, since it uses less digits than its factorization.

66669750 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 408240, while the sum is 45.

The square root of 66669750 is about 8165.1546219285. The cubic root of 66669750 is about 405.4863840939.

The spelling of 66669750 in words is "sixty-six million, six hundred sixty-nine thousand, seven hundred fifty".