628131261 has 4 divisors (see below), whose sum is σ = 837508352. Its totient is φ = 418754172.

The previous prime is 628131253. The next prime is 628131293. The reversal of 628131261 is 162131826.

628131261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 628131261 - 2³ = 628131253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628121261) 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, 104688541 + ... + 104688546.

It is an arithmetic number, because the mean of its divisors is an integer number (209377088).

Almost surely, 2^628131261 is an apocalyptic number.

It is an amenable number.

628131261 is a deficient number, since it is larger than the sum of its proper divisors (209377091).

628131261 is a wasteful number, since it uses less digits than its factorization.

628131261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209377090.

The product of its digits is 3456, while the sum is 30.

The square root of 628131261 is about 25062.5469775121. The cubic root of 628131261 is about 856.4134303918.

The spelling of 628131261 in words is "six hundred twenty-eight million, one hundred thirty-one thousand, two hundred sixty-one".