66820530 has 64 divisors (see below), whose sum is σ = 192936960. Its totient is φ = 14468544.

The previous prime is 66820513. The next prime is 66820547. The reversal of 66820530 is 3502866.

It is an interprime number because it is at equal distance from previous prime (66820513) and next prime (66820547).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4384 + ... + 12363.

It is an arithmetic number, because the mean of its divisors is an integer number (3014640).

Almost surely, 2^66820530 is an apocalyptic number.

66820530 is an abundant number, since it is smaller than the sum of its proper divisors (126116430).

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

66820530 is a wasteful number, since it uses less digits than its factorization.

66820530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16783.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 66820530 is about 8174.3825454893. The cubic root of 66820530 is about 405.7918359871.

The spelling of 66820530 in words is "sixty-six million, eight hundred twenty thousand, five hundred thirty".