33728557 has 4 divisors (see below), whose sum is σ = 35195040. Its totient is φ = 32262076.

The previous prime is 33728551. The next prime is 33728573. The reversal of 33728557 is 75582733.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-33728557 is a prime.

It is a super-2 number, since 2×33728557² = 2275231114604498, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33728551) 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, 733207 + ... + 733252.

It is an arithmetic number, because the mean of its divisors is an integer number (8798760).

Almost surely, 2^33728557 is an apocalyptic number.

It is an amenable number.

33728557 is a deficient number, since it is larger than the sum of its proper divisors (1466483).

33728557 is a wasteful number, since it uses less digits than its factorization.

33728557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1466482.

The product of its digits is 176400, while the sum is 40.

The square root of 33728557 is about 5807.6292064835. The cubic root of 33728557 is about 323.0967482006.

The spelling of 33728557 in words is "thirty-three million, seven hundred twenty-eight thousand, five hundred fifty-seven".