28738557 has 20 divisors (see below), whose sum is σ = 43172316. Its totient is φ = 19051200.

The previous prime is 28738553. The next prime is 28738571. The reversal of 28738557 is 75583782.

28738557 is a `hidden beast` number, since 28 + 73 + 8 + 557 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17589636 + 11148921 = 4194^2 + 3339^2 .

It is not a de Polignac number, because 28738557 - 2² = 28738553 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28738553) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15057 + ... + 16857.

Almost surely, 2^28738557 is an apocalyptic number.

28738557 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

28738557 is a deficient number, since it is larger than the sum of its proper divisors (14433759).

28738557 is a wasteful number, since it uses less digits than its factorization.

28738557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2010 (or 2001 counting only the distinct ones).

The product of its digits is 470400, while the sum is 45.

The square root of 28738557 is about 5360.8354759310. The cubic root of 28738557 is about 306.3056346517.

The spelling of 28738557 in words is "twenty-eight million, seven hundred thirty-eight thousand, five hundred fifty-seven".