66790980 has 108 divisors (see below), whose sum is σ = 210794220. Its totient is φ = 17775936.

The previous prime is 66790979. The next prime is 66790993. The reversal of 66790980 is 8909766.

It can be written as a sum of positive squares in 2 ways, for example, as 39917124 + 26873856 = 6318^2 + 5184^2 .

It is a tau number, because it is divible by the number of its divisors (108).

It is a super-2 number, since 2×66790980² = 8922070018720800, which contains 22 as substring.

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 35 ways as a sum of consecutive naturals, for example, 130966 + ... + 131474.

Almost surely, 2^66790980 is an apocalyptic number.

66790980 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 66790980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105397110).

66790980 is an abundant number, since it is smaller than the sum of its proper divisors (144003240).

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

66790980 is an equidigital number, since it uses as much as digits as its factorization.

66790980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 542 (or 519 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 66790980 is about 8172.5748696479. The cubic root of 66790980 is about 405.7320094797.

The spelling of 66790980 in words is "sixty-six million, seven hundred ninety thousand, nine hundred eighty".