1501581 has 4 divisors (see below), whose sum is σ = 2002112. Its totient is φ = 1001052.

The previous prime is 1501573. The next prime is 1501583. The reversal of 1501581 is 1851051.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1501581 - 2³ = 1501573 is a prime.

It is a super-2 number, since 2×1501581² = 4509490999122, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1501583) 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, 250261 + ... + 250266.

It is an arithmetic number, because the mean of its divisors is an integer number (500528).

2^1501581 is an apocalyptic number.

It is an amenable number.

1501581 is a deficient number, since it is larger than the sum of its proper divisors (500531).

1501581 is an equidigital number, since it uses as much as digits as its factorization.

1501581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500530.

The product of its (nonzero) digits is 200, while the sum is 21.

The square root of 1501581 is about 1225.3901419548. The cubic root of 1501581 is about 114.5116277609.

The spelling of 1501581 in words is "one million, five hundred one thousand, five hundred eighty-one".