1618828638 has 64 divisors (see below), whose sum is σ = 3928393728. Its totient is φ = 434142720.

The previous prime is 1618828577. The next prime is 1618828657. The reversal of 1618828638 is 8368288161.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 280603 + ... + 286313.

It is an arithmetic number, because the mean of its divisors is an integer number (61381152).

Almost surely, 2^1618828638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1618828638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1964196864).

1618828638 is an abundant number, since it is smaller than the sum of its proper divisors (2309565090).

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

1618828638 is a wasteful number, since it uses less digits than its factorization.

1618828638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6137.

The product of its digits is 884736, while the sum is 51.

The square root of 1618828638 is about 40234.6696022224. The cubic root of 1618828638 is about 1174.1771545179.

The spelling of 1618828638 in words is "one billion, six hundred eighteen million, eight hundred twenty-eight thousand, six hundred thirty-eight".