820911966 has 16 divisors (see below), whose sum is σ = 1876370304. Its totient is φ = 234546264.

The previous prime is 820911947. The next prime is 820911977. The reversal of 820911966 is 669119028.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 19545523 = 820911966 / (8 + 2 + 0 + 9 + 1 + 1 + 9 + 6 + 6).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9772720 + ... + 9772803.

It is an arithmetic number, because the mean of its divisors is an integer number (117273144).

Almost surely, 2^820911966 is an apocalyptic number.

820911966 is an abundant number, since it is smaller than the sum of its proper divisors (1055458338).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820911966 is a wasteful number, since it uses less digits than its factorization.

820911966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19545535.

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 820911966 is about 28651.5613187135. The cubic root of 820911966 is about 936.3370220532.

The spelling of 820911966 in words is "eight hundred twenty million, nine hundred eleven thousand, nine hundred sixty-six".