66126481920 has 720 divisors, whose sum is σ = 247415021568. Its totient is φ = 16930529280.

The previous prime is 66126481919. The next prime is 66126481933. The reversal of 66126481920 is 2918462166.

66126481920 is a `hidden beast` number, since 6 + 61 + 26 + 481 + 92 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-2 number, since 2×66126481920² (a number of 22 digits) 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 71 ways as a sum of consecutive naturals, for example, 520680897 + ... + 520681023.

Almost surely, 2^66126481920 is an apocalyptic number.

66126481920 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 66126481920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123707510784).

66126481920 is an abundant number, since it is smaller than the sum of its proper divisors (181288539648).

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

66126481920 is an frugal number, since it uses more digits than its factorization.

66126481920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 66126481920 in words is "sixty-six billion, one hundred twenty-six million, four hundred eighty-one thousand, nine hundred twenty".