306639072 has 72 divisors (see below), whose sum is σ = 873787824. Its totient is φ = 102004224.

The previous prime is 306639037. The next prime is 306639077. The reversal of 306639072 is 270936603.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (306639077) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 213268 + ... + 214700.

It is an arithmetic number, because the mean of its divisors is an integer number (12135942).

Almost surely, 2^306639072 is an apocalyptic number.

306639072 is a gapful number since it is divisible by the number (32) 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 306639072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (436893912).

306639072 is an abundant number, since it is smaller than the sum of its proper divisors (567148752).

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

306639072 is a wasteful number, since it uses less digits than its factorization.

306639072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2192 (or 2181 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 36.

The square root of 306639072 is about 17511.1128144387. The cubic root of 306639072 is about 674.3352006060.

The spelling of 306639072 in words is "three hundred six million, six hundred thirty-nine thousand, seventy-two".