638097281 has 4 divisors (see below), whose sum is σ = 641304000. Its totient is φ = 634890564.

The previous prime is 638097269. The next prime is 638097283. The reversal of 638097281 is 182790836.

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 638097281 - 2¹⁰ = 638096257 is a prime.

It is a super-2 number, since 2×638097281² = 814336280039185922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638097283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1603061 + ... + 1603458.

It is an arithmetic number, because the mean of its divisors is an integer number (160326000).

Almost surely, 2^638097281 is an apocalyptic number.

It is an amenable number.

638097281 is a deficient number, since it is larger than the sum of its proper divisors (3206719).

638097281 is a wasteful number, since it uses less digits than its factorization.

638097281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3206718.

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 638097281 is about 25260.5875030649. The cubic root of 638097281 is about 860.9190108190.

The spelling of 638097281 in words is "six hundred thirty-eight million, ninety-seven thousand, two hundred eighty-one".