1618138656 has 36 divisors (see below), whose sum is σ = 4601582622. Its totient is φ = 539379456.

The previous prime is 1618138631. The next prime is 1618138657. The reversal of 1618138656 is 6568318161.

It can be written as a sum of positive squares in only one way, i.e., 1198544400 + 419594256 = 34620^2 + 20484^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (1618138657) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2808981 + ... + 2809556.

Almost surely, 2^1618138656 is an apocalyptic number.

1618138656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1618138656 is an abundant number, since it is smaller than the sum of its proper divisors (2983443966).

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

1618138656 is a wasteful number, since it uses less digits than its factorization.

1618138656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5618553 (or 5618542 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 1618138656 is about 40226.0942175598. The cubic root of 1618138656 is about 1174.0103103746.

The spelling of 1618138656 in words is "one billion, six hundred eighteen million, one hundred thirty-eight thousand, six hundred fifty-six".