661992 has 16 divisors (see below), whose sum is σ = 1655040. Its totient is φ = 220656.

The previous prime is 661987. The next prime is 661993. The reversal of 661992 is 299166.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (661993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13768 + ... + 13815.

It is an arithmetic number, because the mean of its divisors is an integer number (103440).

2⁶⁶¹⁹⁹² is an apocalyptic number.

It is an amenable number.

661992 is an abundant number, since it is smaller than the sum of its proper divisors (993048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661992 is a wasteful number, since it uses less digits than its factorization.

661992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27592 (or 27588 counting only the distinct ones).

The product of its digits is 5832, while the sum is 33.

The square root of 661992 is about 813.6289080410. The cubic root of 661992 is about 87.1533824837.

It can be divided in two parts, 661 and 992, that added together give a triangular number (1653 = T₅₇).

The spelling of 661992 in words is "six hundred sixty-one thousand, nine hundred ninety-two".