1638020012 has 12 divisors (see below), whose sum is σ = 2868316920. Its totient is φ = 818500896.

The previous prime is 1638019997. The next prime is 1638020071. The reversal of 1638020012 is 2100208361.

It is a self number, because there is not a number n which added to its sum of digits gives 1638020012.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 119993 + ... + 132944.

It is an arithmetic number, because the mean of its divisors is an integer number (239026410).

Almost surely, 2^1638020012 is an apocalyptic number.

It is an amenable number.

1638020012 is a deficient number, since it is larger than the sum of its proper divisors (1230296908).

1638020012 is a wasteful number, since it uses less digits than its factorization.

1638020012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254560 (or 254558 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 1638020012 is about 40472.4599202964. The cubic root of 1638020012 is about 1178.7989339921.

Adding to 1638020012 its reverse (2100208361), we get a palindrome (3738228373).

The spelling of 1638020012 in words is "one billion, six hundred thirty-eight million, twenty thousand, twelve".