1661025210 has 128 divisors (see below), whose sum is σ = 4461198336. Its totient is φ = 393154560.

The previous prime is 1661025173. The next prime is 1661025221. The reversal of 1661025210 is 125201661.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1166559 + ... + 1167981.

It is an arithmetic number, because the mean of its divisors is an integer number (34853112).

Almost surely, 2^1661025210 is an apocalyptic number.

1661025210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1661025210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2230599168).

1661025210 is an abundant number, since it is smaller than the sum of its proper divisors (2800173126).

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

1661025210 is a wasteful number, since it uses less digits than its factorization.

1661025210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1560.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 1661025210 is about 40755.6770278694. The cubic root of 1661025210 is about 1184.2918519982.

Adding to 1661025210 its reverse (125201661), we get a palindrome (1786226871).

The spelling of 1661025210 in words is "one billion, six hundred sixty-one million, twenty-five thousand, two hundred ten".