1550661 has 16 divisors (see below), whose sum is σ = 2421888. Its totient is φ = 864000.

The previous prime is 1550629. The next prime is 1550663. The reversal of 1550661 is 1660551.

It is not a de Polignac number, because 1550661 - 2⁵ = 1550629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1550663) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 40 + ... + 1761.

It is an arithmetic number, because the mean of its divisors is an integer number (151368).

2^1550661 is an apocalyptic number.

It is an amenable number.

1550661 is a deficient number, since it is larger than the sum of its proper divisors (871227).

1550661 is a wasteful number, since it uses less digits than its factorization.

1550661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1852.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 1550661 is about 1245.2553954912. The cubic root of 1550661 is about 115.7459013923.

It can be divided in two parts, 1550 and 661, that added together give a triangular number (2211 = T₆₆).

The spelling of 1550661 in words is "one million, five hundred fifty thousand, six hundred sixty-one".