28309830 has 32 divisors (see below), whose sum is σ = 68905728. Its totient is φ = 7442400.

The previous prime is 28309823. The next prime is 28309837. The reversal of 28309830 is 3890382.

It is an interprime number because it is at equal distance from previous prime (28309823) and next prime (28309837).

It is a junction number, because it is equal to n+sod(n) for n = 28309791 and 28309800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28309837) 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, 4516 + ... + 8775.

It is an arithmetic number, because the mean of its divisors is an integer number (2153304).

Almost surely, 2^28309830 is an apocalyptic number.

28309830 is an abundant number, since it is smaller than the sum of its proper divisors (40595898).

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

28309830 is a wasteful number, since it uses less digits than its factorization.

28309830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13372.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 28309830 is about 5320.6982624464. The cubic root of 28309830 is about 304.7748225978.

It can be divided in two parts, 283098 and 30, that added together give a triangular number (283128 = T₇₅₂).

The spelling of 28309830 in words is "twenty-eight million, three hundred nine thousand, eight hundred thirty".