1971813 has 24 divisors (see below), whose sum is σ = 2977344. Its totient is φ = 1154560.

The previous prime is 1971799. The next prime is 1971829. The reversal of 1971813 is 3181791.

It is not a de Polignac number, because 1971813 - 2¹² = 1967717 is a prime.

Its product of digits (1512) is a multiple of the sum of its prime divisors (84).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1971833) 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 23 ways as a sum of consecutive naturals, for example, 48073 + ... + 48113.

It is an arithmetic number, because the mean of its divisors is an integer number (124056).

2^1971813 is an apocalyptic number.

It is an amenable number.

1971813 is a deficient number, since it is larger than the sum of its proper divisors (1005531).

1971813 is a wasteful number, since it uses less digits than its factorization.

1971813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 84 counting only the distinct ones).

The product of its digits is 1512, while the sum is 30.

The square root of 1971813 is about 1404.2125907426. The cubic root of 1971813 is about 125.3974125008.

The spelling of 1971813 in words is "one million, nine hundred seventy-one thousand, eight hundred thirteen".