28139770 has 8 divisors (see below), whose sum is σ = 50651604. Its totient is φ = 11255904.

The previous prime is 28139747. The next prime is 28139789. The reversal of 28139770 is 7793182.

It can be written as a sum of positive squares in 2 ways, for example, as 27804529 + 335241 = 5273^2 + 579^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1406979 + ... + 1406998.

Almost surely, 2^28139770 is an apocalyptic number.

28139770 is a deficient number, since it is larger than the sum of its proper divisors (22511834).

28139770 is a wasteful number, since it uses less digits than its factorization.

28139770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2813984.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 28139770 is about 5304.6932050779. The cubic root of 28139770 is about 304.1633254986.

The spelling of 28139770 in words is "twenty-eight million, one hundred thirty-nine thousand, seven hundred seventy".