1661516240 has 20 divisors (see below), whose sum is σ = 3863025444. Its totient is φ = 664606464.

The previous prime is 1661516221. The next prime is 1661516257. The reversal of 1661516240 is 426151661.

It can be written as a sum of positive squares in 2 ways, for example, as 1313917504 + 347598736 = 36248^2 + 18644^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 1661516197 and 1661516206.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10384397 + ... + 10384556.

Almost surely, 2^1661516240 is an apocalyptic number.

1661516240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661516240 is an abundant number, since it is smaller than the sum of its proper divisors (2201509204).

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

1661516240 is a wasteful number, since it uses less digits than its factorization.

1661516240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20768966 (or 20768960 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 1661516240 is about 40761.7006514694. The cubic root of 1661516240 is about 1184.4085400795.

The spelling of 1661516240 in words is "one billion, six hundred sixty-one million, five hundred sixteen thousand, two hundred forty".