1531381 has 4 divisors (see below), whose sum is σ = 1612000. Its totient is φ = 1450764.

The previous prime is 1531379. The next prime is 1531447. The reversal of 1531381 is 1831351.

1531381 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1831351 = 73 ⋅25087.

It is not a de Polignac number, because 1531381 - 2¹ = 1531379 is a prime.

It is a super-2 number, since 2×1531381² = 4690255534322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531331) 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, 40281 + ... + 40318.

It is an arithmetic number, because the mean of its divisors is an integer number (403000).

2^1531381 is an apocalyptic number.

It is an amenable number.

1531381 is a deficient number, since it is larger than the sum of its proper divisors (80619).

1531381 is an equidigital number, since it uses as much as digits as its factorization.

1531381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80618.

The product of its digits is 360, while the sum is 22.

The square root of 1531381 is about 1237.4897979377. The cubic root of 1531381 is about 115.2641941038.

The spelling of 1531381 in words is "one million, five hundred thirty-one thousand, three hundred eighty-one".