6638551 has 4 divisors (see below), whose sum is σ = 7029072. Its totient is φ = 6248032.

The previous prime is 6638549. The next prime is 6638579. The reversal of 6638551 is 1558366.

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 6638551 - 2¹ = 6638549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6638531) 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, 195235 + ... + 195268.

It is an arithmetic number, because the mean of its divisors is an integer number (1757268).

Almost surely, 2^6638551 is an apocalyptic number.

6638551 is a deficient number, since it is larger than the sum of its proper divisors (390521).

6638551 is a wasteful number, since it uses less digits than its factorization.

6638551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390520.

The product of its digits is 21600, while the sum is 34.

The square root of 6638551 is about 2576.5385694765. The cubic root of 6638551 is about 187.9422544091.

The spelling of 6638551 in words is "six million, six hundred thirty-eight thousand, five hundred fifty-one".