638422851 has 8 divisors (see below), whose sum is σ = 928615104. Its totient is φ = 386922920.

The previous prime is 638422843. The next prime is 638422853. The reversal of 638422851 is 158224836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 638422851 - 2³ = 638422843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638422853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9673041 + ... + 9673106.

It is an arithmetic number, because the mean of its divisors is an integer number (116076888).

Almost surely, 2^638422851 is an apocalyptic number.

638422851 is a deficient number, since it is larger than the sum of its proper divisors (290192253).

638422851 is a wasteful number, since it uses less digits than its factorization.

638422851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19346161.

The product of its digits is 92160, while the sum is 39.

The square root of 638422851 is about 25267.0309098635. The cubic root of 638422851 is about 861.0654052923.

The spelling of 638422851 in words is "six hundred thirty-eight million, four hundred twenty-two thousand, eight hundred fifty-one".