2661723591 has 24 divisors (see below), whose sum is σ = 3616292736. Its totient is φ = 1741417920.

The previous prime is 2661723587. The next prime is 2661723601. The reversal of 2661723591 is 1953271662.

It is not a de Polignac number, because 2661723591 - 2² = 2661723587 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661723511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5291446 + ... + 5291948.

It is an arithmetic number, because the mean of its divisors is an integer number (150678864).

Almost surely, 2^2661723591 is an apocalyptic number.

2661723591 is a deficient number, since it is larger than the sum of its proper divisors (954569145).

2661723591 is an equidigital number, since it uses as much as digits as its factorization.

2661723591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 983 (or 910 counting only the distinct ones).

The product of its digits is 136080, while the sum is 42.

The square root of 2661723591 is about 51591.8946250281. The cubic root of 2661723591 is about 1385.8651844199.

The spelling of 2661723591 in words is "two billion, six hundred sixty-one million, seven hundred twenty-three thousand, five hundred ninety-one".