66771520 has 112 divisors (see below), whose sum is σ = 168542208. Its totient is φ = 25159680.

The previous prime is 66771473. The next prime is 66771521. The reversal of 66771520 is 2517766.

It is a super-2 number, since 2×66771520² = 8916871766220800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66771521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 525697 + ... + 525823.

Almost surely, 2^66771520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66771520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84271104).

66771520 is an abundant number, since it is smaller than the sum of its proper divisors (101770688).

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

66771520 is a wasteful number, since it uses less digits than its factorization.

66771520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228 (or 218 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 66771520 is about 8171.3842156638. The cubic root of 66771520 is about 405.6926014048.

The spelling of 66771520 in words is "sixty-six million, seven hundred seventy-one thousand, five hundred twenty".