1660561540 has 24 divisors (see below), whose sum is σ = 3804196032. Its totient is φ = 603840480.

The previous prime is 1660561537. The next prime is 1660561583. The reversal of 1660561540 is 451650661.

It is a happy number.

It is a super-4 number, since 4×1660561540⁴ (a number of 38 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1660561496 and 1660561505.

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 7 ways as a sum of consecutive naturals, for example, 3773784 + ... + 3774223.

It is an arithmetic number, because the mean of its divisors is an integer number (158508168).

Almost surely, 2^1660561540 is an apocalyptic number.

1660561540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1660561540 is an abundant number, since it is smaller than the sum of its proper divisors (2143634492).

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

1660561540 is a wasteful number, since it uses less digits than its factorization.

1660561540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7548027 (or 7548025 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 1660561540 is about 40749.9882208572. The cubic root of 1660561540 is about 1184.1816446189.

The spelling of 1660561540 in words is "one billion, six hundred sixty million, five hundred sixty-one thousand, five hundred forty".