1661506210 has 96 divisors (see below), whose sum is σ = 3786637680. Its totient is φ = 520224768.

The previous prime is 1661506199. The next prime is 1661506211. The reversal of 1661506210 is 126051661.

It can be written as a sum of positive squares in 8 ways, for example, as 63345681 + 1598160529 = 7959^2 + 39977^2 .

It is not an unprimeable number, because it can be changed into a prime (1661506211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 616546 + ... + 619234.

Almost surely, 2^1661506210 is an apocalyptic number.

1661506210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1661506210 is an abundant number, since it is smaller than the sum of its proper divisors (2125131470).

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

1661506210 is a wasteful number, since it uses less digits than its factorization.

1661506210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2820 (or 2813 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 1661506210 is about 40761.5776191256. The cubic root of 1661506210 is about 1184.4061567862.

Adding to 1661506210 its reverse (126051661), we get a palindrome (1787557871).

The spelling of 1661506210 in words is "one billion, six hundred sixty-one million, five hundred six thousand, two hundred ten".