661740011 has 4 divisors (see below), whose sum is σ = 700665912. Its totient is φ = 622814112.

The previous prime is 661739987. The next prime is 661740071. The reversal of 661740011 is 110047166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 110047166 = 2 ⋅55023583.

It is a cyclic number.

It is not a de Polignac number, because 661740011 - 2¹⁴ = 661723627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661740071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19462925 + ... + 19462958.

It is an arithmetic number, because the mean of its divisors is an integer number (175166478).

Almost surely, 2^661740011 is an apocalyptic number.

661740011 is a deficient number, since it is larger than the sum of its proper divisors (38925901).

661740011 is a wasteful number, since it uses less digits than its factorization.

661740011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38925900.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 661740011 is about 25724.3077846616. The cubic root of 661740011 is about 871.4232269198.

Adding to 661740011 its reverse (110047166), we get a palindrome (771787177).

The spelling of 661740011 in words is "six hundred sixty-one million, seven hundred forty thousand, eleven".