1665561016 has 32 divisors (see below), whose sum is σ = 3571958880. Its totient is φ = 713232000.

The previous prime is 1665561013. The next prime is 1665561049. The reversal of 1665561016 is 6101655661.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665561013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61426 + ... + 84286.

It is an arithmetic number, because the mean of its divisors is an integer number (111623715).

Almost surely, 2^1665561016 is an apocalyptic number.

It is an amenable number.

1665561016 is an abundant number, since it is smaller than the sum of its proper divisors (1906397864).

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

1665561016 is a wasteful number, since it uses less digits than its factorization.

1665561016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24175 (or 24171 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 1665561016 is about 40811.2853999969. The cubic root of 1665561016 is about 1185.3688647361.

The spelling of 1665561016 in words is "one billion, six hundred sixty-five million, five hundred sixty-one thousand, sixteen".