1641557768 has 8 divisors (see below), whose sum is σ = 3077920830. Its totient is φ = 820778880.

The previous prime is 1641557761. The next prime is 1641557777. The reversal of 1641557768 is 8677551461.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1568318404 + 73239364 = 39602^2 + 8558^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×1641557768² = 5389423811362283648, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1641557761) by changing a digit.

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 as a sum of consecutive naturals, namely, 102597353 + ... + 102597368.

Almost surely, 2^1641557768 is an apocalyptic number.

It is an amenable number.

1641557768 is a deficient number, since it is larger than the sum of its proper divisors (1436363062).

1641557768 is a wasteful number, since it uses less digits than its factorization.

1641557768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205194727 (or 205194723 counting only the distinct ones).

The product of its digits is 1411200, while the sum is 50.

The square root of 1641557768 is about 40516.1420670823. The cubic root of 1641557768 is about 1179.6469709029.

The spelling of 1641557768 in words is "one billion, six hundred forty-one million, five hundred fifty-seven thousand, seven hundred sixty-eight".