1638089764 has 6 divisors (see below), whose sum is σ = 2866657094. Its totient is φ = 819044880.

The previous prime is 1638089753. The next prime is 1638089819. The reversal of 1638089764 is 4679808361.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1635393600 + 2696164 = 40440^2 + 1642^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 204761217 + ... + 204761224.

Almost surely, 2^1638089764 is an apocalyptic number.

It is an amenable number.

1638089764 is a deficient number, since it is larger than the sum of its proper divisors (1228567330).

1638089764 is a wasteful number, since it uses less digits than its factorization.

1638089764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409522445 (or 409522443 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 52.

The square root of 1638089764 is about 40473.3216328979. The cubic root of 1638089764 is about 1178.8156660661.

The spelling of 1638089764 in words is "one billion, six hundred thirty-eight million, eighty-nine thousand, seven hundred sixty-four".