69728257 has 4 divisors (see below), whose sum is σ = 69749680. Its totient is φ = 69706836.

The previous prime is 69728251. The next prime is 69728261. The reversal of 69728257 is 75282796.

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 not a de Polignac number, because 69728257 - 2¹⁹ = 69203969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (69728251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4707 + ... + 12712.

It is an arithmetic number, because the mean of its divisors is an integer number (17437420).

Almost surely, 2^69728257 is an apocalyptic number.

It is an amenable number.

69728257 is a deficient number, since it is larger than the sum of its proper divisors (21423).

69728257 is a wasteful number, since it uses less digits than its factorization.

69728257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21422.

The product of its digits is 423360, while the sum is 46.

The square root of 69728257 is about 8350.3447234231. The cubic root of 69728257 is about 411.5945381852.

The spelling of 69728257 in words is "sixty-nine million, seven hundred twenty-eight thousand, two hundred fifty-seven".