1638314657 has 6 divisors (see below), whose sum is σ = 1905794658. Its totient is φ = 1404269664.

The previous prime is 1638314651. The next prime is 1638314669. The reversal of 1638314657 is 7564138361.

It can be written as a sum of positive squares in only one way, i.e., 1543232656 + 95082001 = 39284^2 + 9751^2 .

It is not a de Polignac number, because 1638314657 - 2¹² = 1638310561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1638314651) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16717448 + ... + 16717545.

It is an arithmetic number, because the mean of its divisors is an integer number (317632443).

Almost surely, 2^1638314657 is an apocalyptic number.

It is an amenable number.

1638314657 is a deficient number, since it is larger than the sum of its proper divisors (267480001).

1638314657 is an equidigital number, since it uses as much as digits as its factorization.

1638314657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33435007 (or 33435000 counting only the distinct ones).

The product of its digits is 362880, while the sum is 44.

The square root of 1638314657 is about 40476.0998244643. The cubic root of 1638314657 is about 1178.8696100493.

The spelling of 1638314657 in words is "one billion, six hundred thirty-eight million, three hundred fourteen thousand, six hundred fifty-seven".