638825149 has 4 divisors (see below), whose sum is σ = 640047136. Its totient is φ = 637603164.

The previous prime is 638825107. The next prime is 638825171. The reversal of 638825149 is 941528836.

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 a cyclic number.

It is not a de Polignac number, because 638825149 - 2¹³ = 638816957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 638825099 and 638825108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638825189) 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, 610209 + ... + 611254.

It is an arithmetic number, because the mean of its divisors is an integer number (160011784).

Almost surely, 2^638825149 is an apocalyptic number.

It is an amenable number.

638825149 is a deficient number, since it is larger than the sum of its proper divisors (1221987).

638825149 is a wasteful number, since it uses less digits than its factorization.

638825149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1221986.

The product of its digits is 414720, while the sum is 46.

The square root of 638825149 is about 25274.9905835789. The cubic root of 638825149 is about 861.2462322336.

The spelling of 638825149 in words is "six hundred thirty-eight million, eight hundred twenty-five thousand, one hundred forty-nine".