638011533 has 4 divisors (see below), whose sum is σ = 850682048. Its totient is φ = 425341020.

The previous prime is 638011531. The next prime is 638011573. The reversal of 638011533 is 335110836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 638011533 - 2¹ = 638011531 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 638011533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638011531) 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, 106335253 + ... + 106335258.

It is an arithmetic number, because the mean of its divisors is an integer number (212670512).

Almost surely, 2^638011533 is an apocalyptic number.

It is an amenable number.

638011533 is a deficient number, since it is larger than the sum of its proper divisors (212670515).

638011533 is a wasteful number, since it uses less digits than its factorization.

638011533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212670514.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 638011533 is about 25258.8901775197. The cubic root of 638011533 is about 860.8804454400.

The spelling of 638011533 in words is "six hundred thirty-eight million, eleven thousand, five hundred thirty-three".