66490020 has 72 divisors (see below), whose sum is σ = 202358520. Its totient is φ = 17671680.

The previous prime is 66490019. The next prime is 66490027. The reversal of 66490020 is 2009466.

It can be written as a sum of positive squares in 4 ways, for example, as 2304 + 66487716 = 48^2 + 8154^2 .

It is not an unprimeable number, because it can be changed into a prime (66490027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 93426 + ... + 94134.

It is an arithmetic number, because the mean of its divisors is an integer number (2810535).

Almost surely, 2^66490020 is an apocalyptic number.

66490020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66490020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101179260).

66490020 is an abundant number, since it is smaller than the sum of its proper divisors (135868500).

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

66490020 is a wasteful number, since it uses less digits than its factorization.

66490020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1245 (or 1240 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 66490020 is about 8154.1412791293. The cubic root of 66490020 is about 405.1216826868.

Adding to 66490020 its reverse (2009466), we get a palindrome (68499486).

The spelling of 66490020 in words is "sixty-six million, four hundred ninety thousand, twenty".