70728769 has 4 divisors (see below), whose sum is σ = 70745796. Its totient is φ = 70711744.

The previous prime is 70728743. The next prime is 70728799. The reversal of 70728769 is 96782707.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 96782707 = 7 ⋅13826101.

It can be written as a sum of positive squares in 2 ways, for example, as 17977600 + 52751169 = 4240^2 + 7263^2 .

It is a cyclic number.

It is not a de Polignac number, because 70728769 - 2⁷ = 70728641 is a prime.

It is a super-2 number, since 2×70728769² = 10005117528510722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (70728799) 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, 2277 + ... + 12109.

It is an arithmetic number, because the mean of its divisors is an integer number (17686449).

Almost surely, 2^70728769 is an apocalyptic number.

It is an amenable number.

70728769 is a deficient number, since it is larger than the sum of its proper divisors (17027).

70728769 is an equidigital number, since it uses as much as digits as its factorization.

70728769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17026.

The product of its (nonzero) digits is 296352, while the sum is 46.

The square root of 70728769 is about 8410.0397739844. The cubic root of 70728769 is about 413.5538165649.

The spelling of 70728769 in words is "seventy million, seven hundred twenty-eight thousand, seven hundred sixty-nine".