66515225280 has 224 divisors, whose sum is σ = 241681138176. Its totient is φ = 15182954496.

The previous prime is 66515225243. The next prime is 66515225297. The reversal of 66515225280 is 8252251566.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5282352 + ... + 5294928.

Almost surely, 2^66515225280 is an apocalyptic number.

66515225280 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 66515225280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120840569088).

66515225280 is an abundant number, since it is smaller than the sum of its proper divisors (175165912896).

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

66515225280 is a wasteful number, since it uses less digits than its factorization.

66515225280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13391 (or 13381 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 42.

The spelling of 66515225280 in words is "sixty-six billion, five hundred fifteen million, two hundred twenty-five thousand, two hundred eighty".