1535661 has 12 divisors (see below), whose sum is σ = 2348892. Its totient is φ = 963456.

The previous prime is 1535629. The next prime is 1535663. The reversal of 1535661 is 1665351.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 864900 + 670761 = 930^2 + 819^2 .

It is not a de Polignac number, because 1535661 - 2⁵ = 1535629 is a prime.

It is an Ulam number.

It is a Curzon number.

1535661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1535663) 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, 4866 + ... + 5171.

It is an arithmetic number, because the mean of its divisors is an integer number (195741).

2^1535661 is an apocalyptic number.

It is an amenable number.

1535661 is a deficient number, since it is larger than the sum of its proper divisors (813231).

1535661 is a wasteful number, since it uses less digits than its factorization.

1535661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10060 (or 10057 counting only the distinct ones).

The product of its digits is 2700, while the sum is 27.

The square root of 1535661 is about 1239.2178985150. The cubic root of 1535661 is about 115.3714767604.

The spelling of 1535661 in words is "one million, five hundred thirty-five thousand, six hundred sixty-one".