2051639 has 4 divisors (see below), whose sum is σ = 2159640. Its totient is φ = 1943640.

The previous prime is 2051629. The next prime is 2051641. The reversal of 2051639 is 9361502.

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 2051639 - 2⁸ = 2051383 is a prime.

It is a super-3 number, since 3×2051639³ = 25907415653331090357, which contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2051629) 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, 53972 + ... + 54009.

It is an arithmetic number, because the mean of its divisors is an integer number (539910).

2^2051639 is an apocalyptic number.

2051639 is a deficient number, since it is larger than the sum of its proper divisors (108001).

2051639 is a wasteful number, since it uses less digits than its factorization.

2051639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108000.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 2051639 is about 1432.3543555978. The cubic root of 2051639 is about 127.0672551787.

The spelling of 2051639 in words is "two million, fifty-one thousand, six hundred thirty-nine".