661455 has 12 divisors (see below), whose sum is σ = 1146600. Its totient is φ = 352752.

The previous prime is 661439. The next prime is 661459. The reversal of 661455 is 554166.

It is a happy number.

It is not a de Polignac number, because 661455 - 2⁴ = 661439 is a prime.

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 in 11 ways as a sum of consecutive naturals, for example, 7305 + ... + 7394.

It is an arithmetic number, because the mean of its divisors is an integer number (95550).

2⁶⁶¹⁴⁵⁵ is an apocalyptic number.

661455 is a deficient number, since it is larger than the sum of its proper divisors (485145).

661455 is a wasteful number, since it uses less digits than its factorization.

661455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14710 (or 14707 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 661455 is about 813.2988380663. The cubic root of 661455 is about 87.1298101812.

It can be divided in two parts, 66 and 1455, that added together give a square (1521 = 39²).

The spelling of 661455 in words is "six hundred sixty-one thousand, four hundred fifty-five".