66939750 has 128 divisors (see below), whose sum is σ = 190494720. Its totient is φ = 17388000.

The previous prime is 66939739. The next prime is 66939787. The reversal of 66939750 is 5793966.

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 = 66939696 and 66939705.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 317145 + ... + 317355.

It is an arithmetic number, because the mean of its divisors is an integer number (1488240).

Almost surely, 2^66939750 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66939750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95247360).

66939750 is an abundant number, since it is smaller than the sum of its proper divisors (123554970).

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

66939750 is a wasteful number, since it uses less digits than its factorization.

66939750 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284 (or 268 counting only the distinct ones).

The product of its (nonzero) digits is 306180, while the sum is 45.

The square root of 66939750 is about 8181.6715895959. The cubic root of 66939750 is about 406.0330281235.

The spelling of 66939750 in words is "sixty-six million, nine hundred thirty-nine thousand, seven hundred fifty".