661723727746 has 16 divisors (see below), whose sum is σ = 1000209339360. Its totient is φ = 328320851040.

The previous prime is 661723727719. The next prime is 661723727773. The reversal of 661723727746 is 647727327166.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (661723727719) and next prime (661723727773).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7305925 + ... + 7395943.

It is an arithmetic number, because the mean of its divisors is an integer number (62513083710).

Almost surely, 2^661723727746 is an apocalyptic number.

661723727746 is a deficient number, since it is larger than the sum of its proper divisors (338485611614).

661723727746 is a wasteful number, since it uses less digits than its factorization.

661723727746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118209.

The product of its digits is 24893568, while the sum is 58.

The spelling of 661723727746 in words is "six hundred sixty-one billion, seven hundred twenty-three million, seven hundred twenty-seven thousand, seven hundred forty-six".