66621240 has 96 divisors (see below), whose sum is σ = 247459680. Its totient is φ = 15227136.

The previous prime is 66621227. The next prime is 66621259. The reversal of 66621240 is 4212666.

It is a happy number.

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, 10699 + ... + 15738.

It is an arithmetic number, because the mean of its divisors is an integer number (2577705).

Almost surely, 2^66621240 is an apocalyptic number.

66621240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66621240 is an abundant number, since it is smaller than the sum of its proper divisors (180838440).

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

66621240 is a wasteful number, since it uses less digits than its factorization.

66621240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26461 (or 26454 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 66621240 is about 8162.1835313842. The cubic root of 66621240 is about 405.3880140575.

The spelling of 66621240 in words is "sixty-six million, six hundred twenty-one thousand, two hundred forty".