660537761 has 8 divisors (see below), whose sum is σ = 712298664. Its totient is φ = 608912640.

The previous prime is 660537751. The next prime is 660537767. The reversal of 660537761 is 167735066.

It can be written as a sum of positive squares in 4 ways, for example, as 41473600 + 619064161 = 6440^2 + 24881^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 660537761 - 2⁶ = 660537697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (660537767) 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, 23720 + ... + 43401.

It is an arithmetic number, because the mean of its divisors is an integer number (89037333).

Almost surely, 2^660537761 is an apocalyptic number.

It is an amenable number.

660537761 is a deficient number, since it is larger than the sum of its proper divisors (51760903).

660537761 is a wasteful number, since it uses less digits than its factorization.

660537761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67891.

The product of its (nonzero) digits is 158760, while the sum is 41.

The square root of 660537761 is about 25700.9291855372. The cubic root of 660537761 is about 870.8951727662.

The spelling of 660537761 in words is "six hundred sixty million, five hundred thirty-seven thousand, seven hundred sixty-one".