820628961 has 8 divisors (see below), whose sum is σ = 1096700640. Its totient is φ = 545821632.

The previous prime is 820628951. The next prime is 820628971. The reversal of 820628961 is 169826028.

It is an interprime number because it is at equal distance from previous prime (820628951) and next prime (820628971).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 820628961 - 2⁵ = 820628929 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (820628911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 314571 + ... + 317168.

It is an arithmetic number, because the mean of its divisors is an integer number (137087580).

Almost surely, 2^820628961 is an apocalyptic number.

It is an amenable number.

820628961 is a deficient number, since it is larger than the sum of its proper divisors (276071679).

820628961 is a wasteful number, since it uses less digits than its factorization.

820628961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 632175.

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 820628961 is about 28646.6221568966. The cubic root of 820628961 is about 936.2294106297.

The spelling of 820628961 in words is "eight hundred twenty million, six hundred twenty-eight thousand, nine hundred sixty-one".