638403414551 has 4 divisors (see below), whose sum is σ = 729603902352. Its totient is φ = 547202926752.

The previous prime is 638403414503. The next prime is 638403414553. The reversal of 638403414551 is 155414304836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638403414551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638403414553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45600243890 + ... + 45600243903.

It is an arithmetic number, because the mean of its divisors is an integer number (182400975588).

Almost surely, 2^638403414551 is an apocalyptic number.

638403414551 is a deficient number, since it is larger than the sum of its proper divisors (91200487801).

638403414551 is an equidigital number, since it uses as much as digits as its factorization.

638403414551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91200487800.

The product of its (nonzero) digits is 691200, while the sum is 44.

The spelling of 638403414551 in words is "six hundred thirty-eight billion, four hundred three million, four hundred fourteen thousand, five hundred fifty-one".