661392 has 40 divisors (see below), whose sum is σ = 1899680. Its totient is φ = 220320.

The previous prime is 661373. The next prime is 661393. The reversal of 661392 is 293166.

It is a happy number.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 661392.

It is not an unprimeable number, because it can be changed into a prime (661393) by changing a digit.

661392 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 334 + ... + 1197.

It is an arithmetic number, because the mean of its divisors is an integer number (47492).

2⁶⁶¹³⁹² is an apocalyptic number.

It is an amenable number.

661392 is an abundant number, since it is smaller than the sum of its proper divisors (1238288).

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

661392 is a wasteful number, since it uses less digits than its factorization.

661392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1548 (or 1536 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 661392 is about 813.2601059932. The cubic root of 661392 is about 87.1270438795.

The spelling of 661392 in words is "six hundred sixty-one thousand, three hundred ninety-two".