2129991 has 8 divisors (see below), whose sum is σ = 2909424. Its totient is φ = 1385280.

The previous prime is 2129983. The next prime is 2130001. The reversal of 2129991 is 1999212.

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

It is not a de Polignac number, because 2129991 - 2³ = 2129983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2129951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8536 + ... + 8781.

It is an arithmetic number, because the mean of its divisors is an integer number (363678).

2^2129991 is an apocalyptic number.

2129991 is a deficient number, since it is larger than the sum of its proper divisors (779433).

2129991 is a wasteful number, since it uses less digits than its factorization.

2129991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17361.

The product of its digits is 2916, while the sum is 33.

The square root of 2129991 is about 1459.4488685802. The cubic root of 2129991 is about 128.6646539040.

The spelling of 2129991 in words is "two million, one hundred twenty-nine thousand, nine hundred ninety-one".