66401580 has 192 divisors, whose sum is σ = 229340160. Its totient is φ = 14017536.

The previous prime is 66401563. The next prime is 66401593. The reversal of 66401580 is 8510466.

66401580 is nontrivially palindromic in base 11.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 422862 + ... + 423018.

It is an arithmetic number, because the mean of its divisors is an integer number (1194480).

Almost surely, 2^66401580 is an apocalyptic number.

66401580 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 66401580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114670080).

66401580 is an abundant number, since it is smaller than the sum of its proper divisors (162938580).

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

66401580 is a wasteful number, since it uses less digits than its factorization.

66401580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 66401580 is about 8148.7164633456. The cubic root of 66401580 is about 404.9419822394.

The spelling of 66401580 in words is "sixty-six million, four hundred one thousand, five hundred eighty".