638346420 has 288 divisors, whose sum is σ = 2191687680. Its totient is φ = 155364480.

The previous prime is 638346367. The next prime is 638346421. The reversal of 638346420 is 24643836.

It is a happy number.

638346420 is a `hidden beast` number, since 6 + 3 + 8 + 3 + 4 + 642 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638346421) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2862429 + ... + 2862651.

Almost surely, 2^638346420 is an apocalyptic number.

638346420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638346420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1095843840).

638346420 is an abundant number, since it is smaller than the sum of its proper divisors (1553341260).

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

638346420 is a wasteful number, since it uses less digits than its factorization.

638346420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297 (or 283 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The square root of 638346420 is about 25265.5183995896. The cubic root of 638346420 is about 861.0310421131.

The spelling of 638346420 in words is "six hundred thirty-eight million, three hundred forty-six thousand, four hundred twenty".