1971321 has 32 divisors (see below), whose sum is σ = 3096576. Its totient is φ = 1104000.

The previous prime is 1971313. The next prime is 1971329. The reversal of 1971321 is 1231791.

It is an interprime number because it is at equal distance from previous prime (1971313) and next prime (1971329).

It is not a de Polignac number, because 1971321 - 2³ = 1971313 is a prime.

It is a super-2 number, since 2×1971321² = 7772212970082, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1971291 and 1971300.

It is not an unprimeable number, because it can be changed into a prime (1971329) 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 31 ways as a sum of consecutive naturals, for example, 41920 + ... + 41966.

It is an arithmetic number, because the mean of its divisors is an integer number (96768).

2^1971321 is an apocalyptic number.

1971321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1971321 is a deficient number, since it is larger than the sum of its proper divisors (1125255).

1971321 is a wasteful number, since it uses less digits than its factorization.

1971321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133.

The product of its digits is 378, while the sum is 24.

The square root of 1971321 is about 1404.0373926645. The cubic root of 1971321 is about 125.3869820561.

The spelling of 1971321 in words is "one million, nine hundred seventy-one thousand, three hundred twenty-one".