66520560 has 40 divisors (see below), whose sum is σ = 206214480. Its totient is φ = 17738752.

The previous prime is 66520547. The next prime is 66520583. The reversal of 66520560 is 6502566.

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 (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138345 + ... + 138824.

It is an arithmetic number, because the mean of its divisors is an integer number (5155362).

Almost surely, 2^66520560 is an apocalyptic number.

66520560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66520560 is an abundant number, since it is smaller than the sum of its proper divisors (139693920).

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

66520560 is a wasteful number, since it uses less digits than its factorization.

66520560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277185 (or 277179 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 66520560 is about 8156.0137322101. The cubic root of 66520560 is about 405.1836996250.

The spelling of 66520560 in words is "sixty-six million, five hundred twenty thousand, five hundred sixty".