1491116761 has 16 divisors (see below), whose sum is σ = 1558781584. Its totient is φ = 1425060864.

The previous prime is 1491116747. The next prime is 1491116773. The reversal of 1491116761 is 1676111941.

It is the 15765-th star number.

It can be written as a sum of positive squares in 8 ways, for example, as 60840000 + 1430276761 = 7800^2 + 37819^2 .

It is a cyclic number.

It is not a de Polignac number, because 1491116761 - 2⁵ = 1491116729 is a prime.

It is a super-2 number, since 2×1491116761² = 4446858389870262242, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a self number, because there is not a number n which added to its sum of digits gives 1491116761.

It is not an unprimeable number, because it can be changed into a prime (1491116161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 747181 + ... + 749173.

It is an arithmetic number, because the mean of its divisors is an integer number (97423849).

Almost surely, 2^1491116761 is an apocalyptic number.

It is an amenable number.

1491116761 is a deficient number, since it is larger than the sum of its proper divisors (67664823).

1491116761 is a wasteful number, since it uses less digits than its factorization.

1491116761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2380.

The product of its digits is 9072, while the sum is 37.

The square root of 1491116761 is about 38614.9810436312. The cubic root of 1491116761 is about 1142.4500402862.

The spelling of 1491116761 in words is "one billion, four hundred ninety-one million, one hundred sixteen thousand, seven hundred sixty-one".