66475511640 has 96 divisors (see below), whose sum is σ = 216077312880. Its totient is φ = 17724185856.

The previous prime is 66475511639. The next prime is 66475511659. The reversal of 66475511640 is 4611557466.

66475511640 is a `hidden beast` number, since 6 + 6 + 4 + 75 + 511 + 64 + 0 = 666.

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 23 ways as a sum of consecutive naturals, for example, 4509562 + ... + 4524278.

Almost surely, 2^66475511640 is an apocalyptic number.

66475511640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66475511640 is an abundant number, since it is smaller than the sum of its proper divisors (149601801240).

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

66475511640 is a wasteful number, since it uses less digits than its factorization.

66475511640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27281 (or 27274 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The spelling of 66475511640 in words is "sixty-six billion, four hundred seventy-five million, five hundred eleven thousand, six hundred forty".