28620291 has 16 divisors (see below), whose sum is σ = 43789824. Its totient is φ = 16287744.

The previous prime is 28620287. The next prime is 28620311. The reversal of 28620291 is 19202682.

It is not a de Polignac number, because 28620291 - 2² = 28620287 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28620281) 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, 2746 + ... + 8048.

It is an arithmetic number, because the mean of its divisors is an integer number (2736864).

Almost surely, 2^28620291 is an apocalyptic number.

28620291 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28620291 is a deficient number, since it is larger than the sum of its proper divisors (15169533).

28620291 is a wasteful number, since it uses less digits than its factorization.

28620291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5570.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 28620291 is about 5349.7935474184. The cubic root of 28620291 is about 305.8848834364.

The spelling of 28620291 in words is "twenty-eight million, six hundred twenty thousand, two hundred ninety-one".