30686320 has 80 divisors (see below), whose sum is σ = 83798208. Its totient is φ = 10229760.

The previous prime is 30686291. The next prime is 30686323. The reversal of 30686320 is 2368603.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30686323) 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, 19980 + ... + 21460.

Almost surely, 2^30686320 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 30686320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41899104).

30686320 is an abundant number, since it is smaller than the sum of its proper divisors (53111888).

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

30686320 is a wasteful number, since it uses less digits than its factorization.

30686320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1538 (or 1532 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 30686320 is about 5539.5234452072. The cubic root of 30686320 is about 313.0749139347.

30686320 divided by its sum of digits (28) gives a triangular number (1095940 = T₁₄₈₀).

The spelling of 30686320 in words is "thirty million, six hundred eighty-six thousand, three hundred twenty".