1201581 has 16 divisors (see below), whose sum is σ = 1797120. Its totient is φ = 793440.

The previous prime is 1201567. The next prime is 1201583. The reversal of 1201581 is 1851021.

It is a de Polignac number, because none of the positive numbers 2^k-1201581 is a prime.

It is a super-2 number, since 2×1201581² = 2887593799122, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201583) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 5041 + ... + 5273.

It is an arithmetic number, because the mean of its divisors is an integer number (112320).

2^1201581 is an apocalyptic number.

It is an amenable number.

1201581 is a deficient number, since it is larger than the sum of its proper divisors (595539).

1201581 is a wasteful number, since it uses less digits than its factorization.

1201581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433 (or 427 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 1201581 is about 1096.1665019512. The cubic root of 1201581 is about 106.3125048602.

The spelling of 1201581 in words is "one million, two hundred one thousand, five hundred eighty-one".