2117961 has 16 divisors (see below), whose sum is σ = 3206400. Its totient is φ = 1381104.

The previous prime is 2117953. The next prime is 2117971. The reversal of 2117961 is 1697112.

It is not a de Polignac number, because 2117961 - 2³ = 2117953 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2117971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 435 + ... + 2103.

It is an arithmetic number, because the mean of its divisors is an integer number (200400).

2^2117961 is an apocalyptic number.

It is an amenable number.

2117961 is a deficient number, since it is larger than the sum of its proper divisors (1088439).

2117961 is a wasteful number, since it uses less digits than its factorization.

2117961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1725 (or 1719 counting only the distinct ones).

The product of its digits is 756, while the sum is 27.

The square root of 2117961 is about 1455.3216139397. The cubic root of 2117961 is about 128.4219675926.

The spelling of 2117961 in words is "two million, one hundred seventeen thousand, nine hundred sixty-one".