661473 has 8 divisors (see below), whose sum is σ = 980000. Its totient is φ = 440964.

The previous prime is 661459. The next prime is 661477. The reversal of 661473 is 374166.

661473 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 661473 - 2⁸ = 661217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 24499 = 661473 / (6 + 6 + 1 + 4 + 7 + 3).

It is a Duffinian number.

661473 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (661477) 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, 12223 + ... + 12276.

It is an arithmetic number, because the mean of its divisors is an integer number (122500).

2⁶⁶¹⁴⁷³ is an apocalyptic number.

It is an amenable number.

661473 is a deficient number, since it is larger than the sum of its proper divisors (318527).

661473 is a wasteful number, since it uses less digits than its factorization.

661473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24508 (or 24502 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 661473 is about 813.3099040341. The cubic root of 661473 is about 87.1306005209.

The spelling of 661473 in words is "six hundred sixty-one thousand, four hundred seventy-three".