1371581 has 2 divisors, whose sum is σ = 1371582. Its totient is φ = 1371580.

The previous prime is 1371569. The next prime is 1371583. The reversal of 1371581 is 1851731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1136356 + 235225 = 1066^2 + 485^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1371581 is a prime.

It is a super-2 number, since 2×1371581² = 3762468879122, which contains 22 as substring.

Together with 1371583, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1371581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1371583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 685790 + 685791.

It is an arithmetic number, because the mean of its divisors is an integer number (685791).

2^1371581 is an apocalyptic number.

It is an amenable number.

1371581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1371581 is an equidigital number, since it uses as much as digits as its factorization.

1371581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 840, while the sum is 26.

The square root of 1371581 is about 1171.1451660661. The cubic root of 1371581 is about 111.1067609038.

The spelling of 1371581 in words is "one million, three hundred seventy-one thousand, five hundred eighty-one".