661694 has 16 divisors (see below), whose sum is σ = 1140480. Its totient is φ = 284760.

The previous prime is 661679. The next prime is 661697. The reversal of 661694 is 496166.

661694 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 661694.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661697) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 374 + ... + 1209.

It is an arithmetic number, because the mean of its divisors is an integer number (71280).

2⁶⁶¹⁶⁹⁴ is an apocalyptic number.

661694 is a deficient number, since it is larger than the sum of its proper divisors (478786).

661694 is a wasteful number, since it uses less digits than its factorization.

661694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615.

The product of its digits is 7776, while the sum is 32.

The square root of 661694 is about 813.4457572574. The cubic root of 661694 is about 87.1403029671.

The spelling of 661694 in words is "six hundred sixty-one thousand, six hundred ninety-four".