66820558 has 32 divisors (see below), whose sum is σ = 117863424. Its totient is φ = 27818592.

The previous prime is 66820547. The next prime is 66820571. The reversal of 66820558 is 85502866.

It is a super-3 number, since 3×66820558³ (a number of 24 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66820558.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113541 + ... + 114127.

It is an arithmetic number, because the mean of its divisors is an integer number (3683232).

Almost surely, 2^66820558 is an apocalyptic number.

66820558 is a deficient number, since it is larger than the sum of its proper divisors (51042866).

66820558 is a wasteful number, since it uses less digits than its factorization.

66820558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816.

The product of its (nonzero) digits is 115200, while the sum is 40.

The square root of 66820558 is about 8174.3842581567. The cubic root of 66820558 is about 405.7918926672.

The spelling of 66820558 in words is "sixty-six million, eight hundred twenty thousand, five hundred fifty-eight".