1661116761 has 8 divisors (see below), whose sum is σ = 2460913760. Its totient is φ = 1107411156.

The previous prime is 1661116753. The next prime is 1661116799. The reversal of 1661116761 is 1676111661.

It is not a de Polignac number, because 1661116761 - 2³ = 1661116753 is a prime.

It is a super-2 number, since 2×1661116761² = 5518617787350262242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1661116711) 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, 30761395 + ... + 30761448.

It is an arithmetic number, because the mean of its divisors is an integer number (307614220).

Almost surely, 2^1661116761 is an apocalyptic number.

It is an amenable number.

1661116761 is a deficient number, since it is larger than the sum of its proper divisors (799796999).

1661116761 is an equidigital number, since it uses as much as digits as its factorization.

1661116761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61522852 (or 61522846 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 1661116761 is about 40756.8001810741. The cubic root of 1661116761 is about 1184.3136098681.

The spelling of 1661116761 in words is "one billion, six hundred sixty-one million, one hundred sixteen thousand, seven hundred sixty-one".