638993712 has 240 divisors, whose sum is σ = 2058201600. Its totient is φ = 169827840.

The previous prime is 638993711. The next prime is 638993713. The reversal of 638993712 is 217399836.

It is an interprime number because it is at equal distance from previous prime (638993711) and next prime (638993713).

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (638993711) 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 47 ways as a sum of consecutive naturals, for example, 3530262 + ... + 3530442.

It is an arithmetic number, because the mean of its divisors is an integer number (8575840).

Almost surely, 2^638993712 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638993712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1029100800).

638993712 is an abundant number, since it is smaller than the sum of its proper divisors (1419207888).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638993712 is a wasteful number, since it uses less digits than its factorization.

638993712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304 (or 291 counting only the distinct ones).

The product of its digits is 489888, while the sum is 48.

The square root of 638993712 is about 25278.3249445053. The cubic root of 638993712 is about 861.3219762156.

The spelling of 638993712 in words is "six hundred thirty-eight million, nine hundred ninety-three thousand, seven hundred twelve".