2139431 has 4 divisors (see below), whose sum is σ = 2445072. Its totient is φ = 1833792.

The previous prime is 2139427. The next prime is 2139461. The reversal of 2139431 is 1349312.

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

It is a cyclic number.

It is not a de Polignac number, because 2139431 - 2² = 2139427 is a prime.

It is a super-2 number, since 2×2139431² = 9154330007522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2139397 and 2139406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2139461) 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, 152810 + ... + 152823.

It is an arithmetic number, because the mean of its divisors is an integer number (611268).

2^2139431 is an apocalyptic number.

2139431 is a deficient number, since it is larger than the sum of its proper divisors (305641).

2139431 is an equidigital number, since it uses as much as digits as its factorization.

2139431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305640.

The product of its digits is 648, while the sum is 23.

The square root of 2139431 is about 1462.6793907073. The cubic root of 2139431 is about 128.8544519517.

The spelling of 2139431 in words is "two million, one hundred thirty-nine thousand, four hundred thirty-one".