661456 has 10 divisors (see below), whose sum is σ = 1281602. Its totient is φ = 330720.

The previous prime is 661439. The next prime is 661459. The reversal of 661456 is 654166.

It can be written as a sum of positive squares in only one way, i.e., 467856 + 193600 = 684^2 + 440^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20655 + ... + 20686.

2⁶⁶¹⁴⁵⁶ is an apocalyptic number.

It is an amenable number.

661456 is a deficient number, since it is larger than the sum of its proper divisors (620146).

661456 is a wasteful number, since it uses less digits than its factorization.

661456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41349 (or 41343 counting only the distinct ones).

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

The square root of 661456 is about 813.2994528462. The cubic root of 661456 is about 87.1298540893.

It can be divided in two parts, 6614 and 56, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 661456 in words is "six hundred sixty-one thousand, four hundred fifty-six".