1561250 has 20 divisors (see below), whose sum is σ = 2928750. Its totient is φ = 624000.

The previous prime is 1561247. The next prime is 1561267. The reversal of 1561250 is 521651.

It can be written as a sum of positive squares in 5 ways, for example, as 6241 + 1555009 = 79^2 + 1247^2 .

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 9 ways as a sum of consecutive naturals, for example, 626 + ... + 1874.

2^1561250 is an apocalyptic number.

1561250 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a pronic number, being equal to 1249×1250.

1561250 is a deficient number, since it is larger than the sum of its proper divisors (1367500).

1561250 is an equidigital number, since it uses as much as digits as its factorization.

1561250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1271 (or 1256 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 1561250 is about 1249.4998999600. The cubic root of 1561250 is about 116.0087686594.

It can be divided in two parts, 156 and 1250, that multiplied together give a triangular number (195000 = T₆₂₄).

The spelling of 1561250 in words is "one million, five hundred sixty-one thousand, two hundred fifty".