628781181 has 24 divisors (see below), whose sum is σ = 996013440. Its totient is φ = 351654912.

The previous prime is 628781177. The next prime is 628781213. The reversal of 628781181 is 181187826.

It is not a de Polignac number, because 628781181 - 2² = 628781177 is a prime.

It is a super-2 number, since 2×628781181² = 790731547159509522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628781081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38596 + ... + 52413.

It is an arithmetic number, because the mean of its divisors is an integer number (41500560).

Almost surely, 2^628781181 is an apocalyptic number.

It is an amenable number.

628781181 is a deficient number, since it is larger than the sum of its proper divisors (367232259).

628781181 is a wasteful number, since it uses less digits than its factorization.

628781181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91073 (or 91066 counting only the distinct ones).

The product of its digits is 43008, while the sum is 42.

The square root of 628781181 is about 25075.5095860483. The cubic root of 628781181 is about 856.7087021990.

The spelling of 628781181 in words is "six hundred twenty-eight million, seven hundred eighty-one thousand, one hundred eighty-one".