28739057 has 4 divisors (see below), whose sum is σ = 28759920. Its totient is φ = 28718196.

The previous prime is 28739021. The next prime is 28739059. The reversal of 28739057 is 75093782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75093782 = 2 ⋅37546891.

It is a cyclic number.

It is not a de Polignac number, because 28739057 - 2¹⁰ = 28738033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28739059) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8207 + ... + 11172.

It is an arithmetic number, because the mean of its divisors is an integer number (7189980).

Almost surely, 2^28739057 is an apocalyptic number.

It is an amenable number.

28739057 is a deficient number, since it is larger than the sum of its proper divisors (20863).

28739057 is a wasteful number, since it uses less digits than its factorization.

28739057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20862.

The product of its (nonzero) digits is 105840, while the sum is 41.

The square root of 28739057 is about 5360.8821102501. The cubic root of 28739057 is about 306.3074110333.

The spelling of 28739057 in words is "twenty-eight million, seven hundred thirty-nine thousand, fifty-seven".