615381640 has 64 divisors (see below), whose sum is σ = 1475107200. Its totient is φ = 230243328.

The previous prime is 615381601. The next prime is 615381647. The reversal of 615381640 is 46183516.

It is a happy number.

615381640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 615381596 and 615381605.

It is not an unprimeable number, because it can be changed into a prime (615381647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110851 + ... + 116269.

It is an arithmetic number, because the mean of its divisors is an integer number (23048550).

Almost surely, 2^615381640 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 615381640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (737553600).

615381640 is an abundant number, since it is smaller than the sum of its proper divisors (859725560).

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

615381640 is a wasteful number, since it uses less digits than its factorization.

615381640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5614 (or 5610 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 615381640 is about 24806.8869469750. The cubic root of 615381640 is about 850.5793697111.

The spelling of 615381640 in words is "six hundred fifteen million, three hundred eighty-one thousand, six hundred forty".