66461420560 has 40 divisors (see below), whose sum is σ = 154578142080. Its totient is φ = 26575047552.

The previous prime is 66461420539. The next prime is 66461420569. The reversal of 66461420560 is 6502416466.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (66461420569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78169 + ... + 372871.

It is an arithmetic number, because the mean of its divisors is an integer number (3864453552).

Almost surely, 2^66461420560 is an apocalyptic number.

It is an amenable number.

66461420560 is an abundant number, since it is smaller than the sum of its proper divisors (88116721520).

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

66461420560 is a wasteful number, since it uses less digits than its factorization.

66461420560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297535 (or 297529 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 40.

The spelling of 66461420560 in words is "sixty-six billion, four hundred sixty-one million, four hundred twenty thousand, five hundred sixty".