1638451330 has 16 divisors (see below), whose sum is σ = 3122695800. Its totient is φ = 616828672.

The previous prime is 1638451327. The next prime is 1638451333. The reversal of 1638451330 is 331548361.

It is an interprime number because it is at equal distance from previous prime (1638451327) and next prime (1638451333).

It can be written as a sum of positive squares in 4 ways, for example, as 1108024369 + 530426961 = 33287^2 + 23031^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (1638451333) 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 7 ways as a sum of consecutive naturals, for example, 4818805 + ... + 4819144.

Almost surely, 2^1638451330 is an apocalyptic number.

1638451330 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1638451330 is a deficient number, since it is larger than the sum of its proper divisors (1484244470).

1638451330 is a wasteful number, since it uses less digits than its factorization.

1638451330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9637973.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 1638451330 is about 40477.7881065653. The cubic root of 1638451330 is about 1178.9023907213.

Adding to 1638451330 its reverse (331548361), we get a palindrome (1969999691).

The spelling of 1638451330 in words is "one billion, six hundred thirty-eight million, four hundred fifty-one thousand, three hundred thirty".