1023561 has 36 divisors (see below), whose sum is σ = 1885104. Its totient is φ = 529200.

The previous prime is 1023557. The next prime is 1023571. The reversal of 1023561 is 1653201.

1023561 is a `hidden beast` number, since 102 + 3 + 561 = 666.

It is not a de Polignac number, because 1023561 - 2² = 1023557 is a prime.

1023561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1023521) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4746 + ... + 4956.

It is an arithmetic number, because the mean of its divisors is an integer number (52364).

2^1023561 is an apocalyptic number.

1023561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1023561 is a deficient number, since it is larger than the sum of its proper divisors (861543).

1023561 is a wasteful number, since it uses less digits than its factorization.

1023561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 1023561 is about 1011.7119155175. The cubic root of 1023561 is about 100.7792781478.

Adding to 1023561 its reverse (1653201), we get a palindrome (2676762).

It can be divided in two parts, 10235 and 61, that added together give a triangular number (10296 = T₁₄₃).

The spelling of 1023561 in words is "one million, twenty-three thousand, five hundred sixty-one".