66621590 has 32 divisors (see below), whose sum is σ = 137355264. Its totient is φ = 22790880.

The previous prime is 66621587. The next prime is 66621617. The reversal of 66621590 is 9512666.

It is a happy number.

66621590 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 66621590.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44555 + ... + 46025.

It is an arithmetic number, because the mean of its divisors is an integer number (4292352).

Almost surely, 2^66621590 is an apocalyptic number.

66621590 is an abundant number, since it is smaller than the sum of its proper divisors (70733674).

66621590 is a wasteful number, since it uses less digits than its factorization.

66621590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2132.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 66621590 is about 8162.2049716973. The cubic root of 66621590 is about 405.3887239691.

The spelling of 66621590 in words is "sixty-six million, six hundred twenty-one thousand, five hundred ninety".