1501561 has 2 divisors, whose sum is σ = 1501562. Its totient is φ = 1501560.

The previous prime is 1501541. The next prime is 1501573. The reversal of 1501561 is 1651051.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1071225 + 430336 = 1035^2 + 656^2 .

It is a cyclic number.

It is not a de Polignac number, because 1501561 - 2⁵ = 1501529 is a prime.

It is not a weakly prime, because it can be changed into another prime (1501501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 750780 + 750781.

It is an arithmetic number, because the mean of its divisors is an integer number (750781).

2^1501561 is an apocalyptic number.

It is an amenable number.

1501561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1501561 is an equidigital number, since it uses as much as digits as its factorization.

1501561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 150, while the sum is 19.

The square root of 1501561 is about 1225.3819812614. The cubic root of 1501561 is about 114.5111193539.

It can be divided in two parts, 150 and 1561, that added together give a triangular number (1711 = T₅₈).

The spelling of 1501561 in words is "one million, five hundred one thousand, five hundred sixty-one".