28308402 has 12 divisors (see below), whose sum is σ = 61334910. Its totient is φ = 9436128.

The previous prime is 28308359. The next prime is 28308403. The reversal of 28308402 is 20480382.

It can be written as a sum of positive squares in only one way, i.e., 28291761 + 16641 = 5319^2 + 129^2 .

It is not an unprimeable number, because it can be changed into a prime (28308403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 786327 + ... + 786362.

Almost surely, 2^28308402 is an apocalyptic number.

28308402 is an abundant number, since it is smaller than the sum of its proper divisors (33026508).

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

28308402 is a wasteful number, since it uses less digits than its factorization.

28308402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1572697 (or 1572694 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 28308402 is about 5320.5640678409. The cubic root of 28308402 is about 304.7696980437.

Adding to 28308402 its reverse (20480382), we get a palindrome (48788784).

The spelling of 28308402 in words is "twenty-eight million, three hundred eight thousand, four hundred two".