2139961 has 4 divisors (see below), whose sum is σ = 2209024. Its totient is φ = 2070900.

The previous prime is 2139959. The next prime is 2139967. The reversal of 2139961 is 1699312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2139961 - 2¹ = 2139959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 69031 = 2139961 / (2 + 1 + 3 + 9 + 9 + 6 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2139967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34485 + ... + 34546.

It is an arithmetic number, because the mean of its divisors is an integer number (552256).

2^2139961 is an apocalyptic number.

It is an amenable number.

2139961 is a deficient number, since it is larger than the sum of its proper divisors (69063).

2139961 is an equidigital number, since it uses as much as digits as its factorization.

2139961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69062.

The product of its digits is 2916, while the sum is 31.

The square root of 2139961 is about 1462.8605538465. The cubic root of 2139961 is about 128.8650914194.

The spelling of 2139961 in words is "two million, one hundred thirty-nine thousand, nine hundred sixty-one".