1291381 has 16 divisors (see below), whose sum is σ = 1661184. Its totient is φ = 975744.

The previous prime is 1291379. The next prime is 1291387. The reversal of 1291381 is 1831921.

It is not a de Polignac number, because 1291381 - 2¹ = 1291379 is a prime.

It is a super-2 number, since 2×1291381² = 3335329774322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291387) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1785 + ... + 2401.

It is an arithmetic number, because the mean of its divisors is an integer number (103824).

2^1291381 is an apocalyptic number.

It is an amenable number.

1291381 is a deficient number, since it is larger than the sum of its proper divisors (369803).

1291381 is a wasteful number, since it uses less digits than its factorization.

1291381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660.

The product of its digits is 432, while the sum is 25.

The square root of 1291381 is about 1136.3894578884. The cubic root of 1291381 is about 108.8975554596.

The spelling of 1291381 in words is "one million, two hundred ninety-one thousand, three hundred eighty-one".