30786640 has 60 divisors (see below), whose sum is σ = 73487484. Its totient is φ = 11994112.

The previous prime is 30786629. The next prime is 30786647. The reversal of 30786640 is 4668703.

It can be written as a sum of positive squares in 6 ways, for example, as 1236544 + 29550096 = 1112^2 + 5436^2 .

It is a junction number, because it is equal to n+sod(n) for n = 30786596 and 30786605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30786647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 224652 + ... + 224788.

Almost surely, 2^30786640 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 30786640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36743742).

30786640 is an abundant number, since it is smaller than the sum of its proper divisors (42700844).

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

30786640 is a wasteful number, since it uses less digits than its factorization.

30786640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256 (or 197 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 30786640 is about 5548.5709872002. The cubic root of 30786640 is about 313.4157119549.

The spelling of 30786640 in words is "thirty million, seven hundred eighty-six thousand, six hundred forty".