820277661 has 32 divisors (see below), whose sum is σ = 1286316288. Its totient is φ = 455270400.

The previous prime is 820277609. The next prime is 820277669. The reversal of 820277661 is 166772028.

820277661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 820277661 - 2⁷ = 820277533 is a prime.

It is a super-2 number, since 2×820277661² = 1345710882271261842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820277669) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108765 + ... + 116061.

It is an arithmetic number, because the mean of its divisors is an integer number (40197384).

Almost surely, 2^820277661 is an apocalyptic number.

It is an amenable number.

820277661 is a deficient number, since it is larger than the sum of its proper divisors (466038627).

820277661 is a wasteful number, since it uses less digits than its factorization.

820277661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7461.

The product of its (nonzero) digits is 56448, while the sum is 39.

The square root of 820277661 is about 28640.4898875700. The cubic root of 820277661 is about 936.0957959061.

The spelling of 820277661 in words is "eight hundred twenty million, two hundred seventy-seven thousand, six hundred sixty-one".