661072711 has 8 divisors (see below), whose sum is σ = 720937280. Its totient is φ = 602495712.

The previous prime is 661072697. The next prime is 661072721. The reversal of 661072711 is 117270166.

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

It is not a de Polignac number, because 661072711 - 2⁵ = 661072679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661072721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320820 + ... + 322873.

It is an arithmetic number, because the mean of its divisors is an integer number (90117160).

Almost surely, 2^661072711 is an apocalyptic number.

661072711 is a deficient number, since it is larger than the sum of its proper divisors (59864569).

661072711 is a wasteful number, since it uses less digits than its factorization.

661072711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643785.

The product of its (nonzero) digits is 3528, while the sum is 31.

The square root of 661072711 is about 25711.3342905420. The cubic root of 661072711 is about 871.1302134092.

The spelling of 661072711 in words is "six hundred sixty-one million, seventy-two thousand, seven hundred eleven".