1563531 has 4 divisors (see below), whose sum is σ = 2084712. Its totient is φ = 1042352.

The previous prime is 1563511. The next prime is 1563533. The reversal of 1563531 is 1353651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1563531 - 2⁶ = 1563467 is a prime.

It is a super-2 number, since 2×1563531² = 4889258375922, which contains 22 as substring.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (1563533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260586 + ... + 260591.

It is an arithmetic number, because the mean of its divisors is an integer number (521178).

2^1563531 is an apocalyptic number.

1563531 is a deficient number, since it is larger than the sum of its proper divisors (521181).

1563531 is an equidigital number, since it uses as much as digits as its factorization.

1563531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521180.

The product of its digits is 1350, while the sum is 24.

The square root of 1563531 is about 1250.4123319929. The cubic root of 1563531 is about 116.0652377786.

It can be divided in two parts, 15 and 63531, that added together give a triangular number (63546 = T₃₅₆).

The spelling of 1563531 in words is "one million, five hundred sixty-three thousand, five hundred thirty-one".