720128655 has 24 divisors (see below), whose sum is σ = 1249296048. Its totient is φ = 383738496.

The previous prime is 720128639. The next prime is 720128659. The reversal of 720128655 is 556821027.

It is a happy number.

It is not a de Polignac number, because 720128655 - 2⁴ = 720128639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720128659) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51499 + ... + 63971.

It is an arithmetic number, because the mean of its divisors is an integer number (52054002).

Almost surely, 2^720128655 is an apocalyptic number.

720128655 is a deficient number, since it is larger than the sum of its proper divisors (529167393).

720128655 is a wasteful number, since it uses less digits than its factorization.

720128655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13767 (or 13764 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 720128655 is about 26835.2129672936. The cubic root of 720128655 is about 896.3343308661.

Subtracting from 720128655 its reverse (556821027), we obtain a triangular number (163307628 = T₁₈₀₇₂).

The spelling of 720128655 in words is "seven hundred twenty million, one hundred twenty-eight thousand, six hundred fifty-five".