2758639 has 4 divisors (see below), whose sum is σ = 2970856. Its totient is φ = 2546424.

The previous prime is 2758633. The next prime is 2758661. The reversal of 2758639 is 9368572.

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 2758639 - 2³ = 2758631 is a prime.

It is a super-2 number, since 2×2758639² = 15220178264642, which contains 22 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 (2758631) 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, 106089 + ... + 106114.

It is an arithmetic number, because the mean of its divisors is an integer number (742714).

2^2758639 is an apocalyptic number.

2758639 is a deficient number, since it is larger than the sum of its proper divisors (212217).

2758639 is a wasteful number, since it uses less digits than its factorization.

2758639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212216.

The product of its digits is 90720, while the sum is 40.

The square root of 2758639 is about 1660.9151092094. The cubic root of 2758639 is about 140.2485211614.

It can be divided in two parts, 2 and 758639, that added together give a square (758641 = 871²).

The spelling of 2758639 in words is "two million, seven hundred fifty-eight thousand, six hundred thirty-nine".