66541890 has 16 divisors (see below), whose sum is σ = 159700608. Its totient is φ = 17744496.

The previous prime is 66541889. The next prime is 66541901. The reversal of 66541890 is 9814566.

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, 1109002 + ... + 1109061.

It is an arithmetic number, because the mean of its divisors is an integer number (9981288).

Almost surely, 2^66541890 is an apocalyptic number.

66541890 is an abundant number, since it is smaller than the sum of its proper divisors (93158718).

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

66541890 is a wasteful number, since it uses less digits than its factorization.

66541890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2218073.

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 66541890 is about 8157.3212514894. The cubic root of 66541890 is about 405.2270027517.

The spelling of 66541890 in words is "sixty-six million, five hundred forty-one thousand, eight hundred ninety".