638147049 has 4 divisors (see below), whose sum is σ = 850862736. Its totient is φ = 425431364.

The previous prime is 638147039. The next prime is 638147051. The reversal of 638147049 is 940741836.

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 638147049 - 2⁵ = 638147017 is a prime.

It is a super-2 number, since 2×638147049² = 814463312294816802, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 638147049.

It is not an unprimeable number, because it can be changed into a prime (638147039) 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, 106357839 + ... + 106357844.

It is an arithmetic number, because the mean of its divisors is an integer number (212715684).

Almost surely, 2^638147049 is an apocalyptic number.

It is an amenable number.

638147049 is a deficient number, since it is larger than the sum of its proper divisors (212715687).

638147049 is a wasteful number, since it uses less digits than its factorization.

638147049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212715686.

The product of its (nonzero) digits is 145152, while the sum is 42.

The square root of 638147049 is about 25261.5725757523. The cubic root of 638147049 is about 860.9413925178.

The spelling of 638147049 in words is "six hundred thirty-eight million, one hundred forty-seven thousand, forty-nine".