66977280 has 400 divisors, whose sum is σ = 267371280. Its totient is φ = 15925248.

The previous prime is 66977279. The next prime is 66977291. The reversal of 66977280 is 8277966.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3525111 + ... + 3525129.

Almost surely, 2^66977280 is an apocalyptic number.

66977280 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 66977280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133685640).

66977280 is an abundant number, since it is smaller than the sum of its proper divisors (200394000).

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

66977280 is a wasteful number, since it uses less digits than its factorization.

66977280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The square root of 66977280 is about 8183.9648093085. The cubic root of 66977280 is about 406.1088952160.

The spelling of 66977280 in words is "sixty-six million, nine hundred seventy-seven thousand, two hundred eighty".