1521381 has 16 divisors (see below), whose sum is σ = 2242944. Its totient is φ = 912384.

The previous prime is 1521371. The next prime is 1521391. The reversal of 1521381 is 1831251.

It is an interprime number because it is at equal distance from previous prime (1521371) and next prime (1521391).

It is not a de Polignac number, because 1521381 - 2¹⁰ = 1520357 is a prime.

It is a super-2 number, since 2×1521381² = 4629200294322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1521301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 525 + ... + 1821.

It is an arithmetic number, because the mean of its divisors is an integer number (140184).

2^1521381 is an apocalyptic number.

It is an amenable number.

1521381 is a deficient number, since it is larger than the sum of its proper divisors (721563).

1521381 is a wasteful number, since it uses less digits than its factorization.

1521381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1340.

The product of its digits is 240, while the sum is 21.

The square root of 1521381 is about 1233.4427428949. The cubic root of 1521381 is about 115.0127522091.

The spelling of 1521381 in words is "one million, five hundred twenty-one thousand, three hundred eighty-one".