28231969 has 2 divisors, whose sum is σ = 28231970. Its totient is φ = 28231968.

The previous prime is 28231963. The next prime is 28232003. The reversal of 28231969 is 96913282.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14630625 + 13601344 = 3825^2 + 3688^2 .

It is a cyclic number.

It is not a de Polignac number, because 28231969 - 2³ = 28231961 is a prime.

It is a super-2 number, since 2×28231969² = 1594088147233922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28231961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14115984 + 14115985.

It is an arithmetic number, because the mean of its divisors is an integer number (14115985).

Almost surely, 2^28231969 is an apocalyptic number.

It is an amenable number.

28231969 is a deficient number, since it is larger than the sum of its proper divisors (1).

28231969 is an equidigital number, since it uses as much as digits as its factorization.

28231969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 40.

The square root of 28231969 is about 5313.3764218245. The cubic root of 28231969 is about 304.4951569500.

The spelling of 28231969 in words is "twenty-eight million, two hundred thirty-one thousand, nine hundred sixty-nine".