66696840 has 288 divisors, whose sum is σ = 266760000. Its totient is φ = 14370048.

The previous prime is 66696823. The next prime is 66696869. The reversal of 66696840 is 4869666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 335061 + ... + 335259.

It is an arithmetic number, because the mean of its divisors is an integer number (926250).

Almost surely, 2^66696840 is an apocalyptic number.

66696840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66696840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133380000).

66696840 is an abundant number, since it is smaller than the sum of its proper divisors (200063160).

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

66696840 is a wasteful number, since it uses less digits than its factorization.

66696840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 66696840 is about 8166.8133320164. The cubic root of 66696840 is about 405.5412972476.

The spelling of 66696840 in words is "sixty-six million, six hundred ninety-six thousand, eight hundred forty".