1561924 has 36 divisors (see below), whose sum is σ = 3429804. Its totient is φ = 616896.

The previous prime is 1561919. The next prime is 1562051. The reversal of 1561924 is 4291651.

It can be written as a sum of positive squares in 2 ways, for example, as 78400 + 1483524 = 280^2 + 1218^2 .

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 1561892 and 1561901.

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 11 ways as a sum of consecutive naturals, for example, 2242 + ... + 2854.

2^1561924 is an apocalyptic number.

1561924 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561924, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1714902).

1561924 is an abundant number, since it is smaller than the sum of its proper divisors (1867880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1561924 is a wasteful number, since it uses less digits than its factorization.

1561924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644 (or 635 counting only the distinct ones).

The product of its digits is 2160, while the sum is 28.

The square root of 1561924 is about 1249.7695787624. The cubic root of 1561924 is about 116.0254601269.

It can be divided in two parts, 1561 and 924, that added together give a triangular number (2485 = T₇₀).

The spelling of 1561924 in words is "one million, five hundred sixty-one thousand, nine hundred twenty-four".