66261880 has 32 divisors (see below), whose sum is σ = 153901440. Its totient is φ = 25649280.

The previous prime is 66261859. The next prime is 66261887. The reversal of 66261880 is 8816266.

It is a super-2 number, since 2×66261880² = 8781273482268800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66261887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25479 + ... + 27958.

It is an arithmetic number, because the mean of its divisors is an integer number (4809420).

Almost surely, 2^66261880 is an apocalyptic number.

It is an amenable number.

66261880 is an abundant number, since it is smaller than the sum of its proper divisors (87639560).

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

66261880 is a wasteful number, since it uses less digits than its factorization.

66261880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53479 (or 53475 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 66261880 is about 8140.1400479353. The cubic root of 66261880 is about 404.6578016846.

The spelling of 66261880 in words is "sixty-six million, two hundred sixty-one thousand, eight hundred eighty".