2131961 has 4 divisors (see below), whose sum is σ = 2295972. Its totient is φ = 1967952.

The previous prime is 2131951. The next prime is 2131979. The reversal of 2131961 is 1691312.

It is a happy number.

2131961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 295936 + 1836025 = 544^2 + 1355^2 .

It is a cyclic number.

It is not a de Polignac number, because 2131961 - 2¹⁰ = 2130937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2131951) 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 3 ways as a sum of consecutive naturals, for example, 81986 + ... + 82011.

It is an arithmetic number, because the mean of its divisors is an integer number (573993).

2^2131961 is an apocalyptic number.

It is an amenable number.

2131961 is a deficient number, since it is larger than the sum of its proper divisors (164011).

2131961 is a wasteful number, since it uses less digits than its factorization.

2131961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164010.

The product of its digits is 324, while the sum is 23.

The square root of 2131961 is about 1460.1236249030. The cubic root of 2131961 is about 128.7043084166.

The spelling of 2131961 in words is "two million, one hundred thirty-one thousand, nine hundred sixty-one".