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30689280 = 21134537

30689280 has 240 divisors, whose sum is σ = 112972860. Its totient is φ = 7962624.

The previous prime is 30689249. The next prime is 30689293. The reversal of 30689280 is 8298603.

It can be written as a sum of positive squares in 2 ways, for example, as 29942784 + 746496 = 5472^2 + 864^2 .

It is a tau number, because it is divible by the number of its divisors (240).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 829422 + ... + 829458.

Almost surely, 230689280 is an apocalyptic number.

30689280 is a gapful number since it is divisible by the number (30) 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 30689280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56486430).

30689280 is an abundant number, since it is smaller than the sum of its proper divisors (82283580).

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

30689280 is an equidigital number, since it uses as much as digits as its factorization.

30689280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 30689280 is about 5539.7906097613. The cubic root of 30689280 is about 313.0849800049.

The spelling of 30689280 in words is "thirty million, six hundred eighty-nine thousand, two hundred eighty".