661740071 has 2 divisors, whose sum is σ = 661740072. Its totient is φ = 661740070.

The previous prime is 661739987. The next prime is 661740097. The reversal of 661740071 is 170047166.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661740071 - 2¹⁰ = 661739047 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661770071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330870035 + 330870036.

It is an arithmetic number, because the mean of its divisors is an integer number (330870036).

Almost surely, 2^661740071 is an apocalyptic number.

661740071 is a deficient number, since it is larger than the sum of its proper divisors (1).

661740071 is an equidigital number, since it uses as much as digits as its factorization.

661740071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 661740071 is about 25724.3089508737. The cubic root of 661740071 is about 871.4232532571.

The spelling of 661740071 in words is "six hundred sixty-one million, seven hundred forty thousand, seventy-one".