661490 has 16 divisors (see below), whose sum is σ = 1232280. Its totient is φ = 255360.

The previous prime is 661483. The next prime is 661513. The reversal of 661490 is 94166.

It can be written as a sum of positive squares in 4 ways, for example, as 561001 + 100489 = 749^2 + 317^2 .

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 851 + ... + 1430.

2⁶⁶¹⁴⁹⁰ is an apocalyptic number.

661490 is a deficient number, since it is larger than the sum of its proper divisors (570790).

661490 is a wasteful number, since it uses less digits than its factorization.

661490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2317.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 661490 is about 813.3203550877. The cubic root of 661490 is about 87.1313469396.

The spelling of 661490 in words is "six hundred sixty-one thousand, four hundred ninety".