661546 has 12 divisors (see below), whose sum is σ = 1024002. Its totient is φ = 320424.

The previous prime is 661541. The next prime is 661547. The reversal of 661546 is 645166.

It can be written as a sum of positive squares in only one way, i.e., 505521 + 156025 = 711^2 + 395^2 .

It is a super-2 number, since 2×661546² = 875286220232, which contains 22 as substring.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (661541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8335 + ... + 8413.

2⁶⁶¹⁵⁴⁶ is an apocalyptic number.

661546 is a deficient number, since it is larger than the sum of its proper divisors (362456).

661546 is an equidigital number, since it uses as much as digits as its factorization.

661546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213 (or 134 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 661546 is about 813.3547811380. The cubic root of 661546 is about 87.1338056403.

The spelling of 661546 in words is "six hundred sixty-one thousand, five hundred forty-six".