661774073 has 16 divisors (see below), whose sum is σ = 682106880. Its totient is φ = 641858256.

The previous prime is 661774067. The next prime is 661774093. The reversal of 661774073 is 370477166.

It is a cyclic number.

It is not a de Polignac number, because 661774073 - 2⁸ = 661773817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 661774073.

It is not an unprimeable number, because it can be changed into a prime (661774093) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1358636 + ... + 1359122.

It is an arithmetic number, because the mean of its divisors is an integer number (42631680).

Almost surely, 2^661774073 is an apocalyptic number.

It is an amenable number.

661774073 is a deficient number, since it is larger than the sum of its proper divisors (20332807).

661774073 is a wasteful number, since it uses less digits than its factorization.

661774073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 836.

The product of its (nonzero) digits is 148176, while the sum is 41.

The square root of 661774073 is about 25724.9698347734. The cubic root of 661774073 is about 871.4381783651.

The spelling of 661774073 in words is "six hundred sixty-one million, seven hundred seventy-four thousand, seventy-three".