1618259640 has 128 divisors (see below), whose sum is σ = 5128704000. Its totient is φ = 407351808.

The previous prime is 1618259623. The next prime is 1618259701. The reversal of 1618259640 is 469528161.

It is a junction number, because it is equal to n+sod(n) for n = 1618259592 and 1618259601.

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, 721641 + ... + 723879.

It is an arithmetic number, because the mean of its divisors is an integer number (40068000).

Almost surely, 2^1618259640 is an apocalyptic number.

1618259640 is a gapful number since it is divisible by the number (10) 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 1618259640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2564352000).

1618259640 is an abundant number, since it is smaller than the sum of its proper divisors (3510444360).

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

1618259640 is a wasteful number, since it uses less digits than its factorization.

1618259640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2589 (or 2585 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 42.

The square root of 1618259640 is about 40227.5979894400. The cubic root of 1618259640 is about 1174.0395688734.

The spelling of 1618259640 in words is "one billion, six hundred eighteen million, two hundred fifty-nine thousand, six hundred forty".