2131978 has 8 divisors (see below), whose sum is σ = 3258468. Its totient is φ = 1045824.

The previous prime is 2131951. The next prime is 2131979. The reversal of 2131978 is 8791312.

It can be written as a sum of positive squares in 2 ways, for example, as 2082249 + 49729 = 1443^2 + 223^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (2131979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9951 + ... + 10162.

2^2131978 is an apocalyptic number.

2131978 is a deficient number, since it is larger than the sum of its proper divisors (1126490).

2131978 is a wasteful number, since it uses less digits than its factorization.

2131978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20168.

The product of its digits is 3024, while the sum is 31.

The square root of 2131978 is about 1460.1294463163. The cubic root of 2131978 is about 128.7046505066.

The spelling of 2131978 in words is "two million, one hundred thirty-one thousand, nine hundred seventy-eight".