820667904 has 160 divisors (see below), whose sum is σ = 2522505216. Its totient is φ = 232243200.

The previous prime is 820667833. The next prime is 820667909. The reversal of 820667904 is 409766028.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820667909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1365204 + ... + 1365804.

Almost surely, 2^820667904 is an apocalyptic number.

820667904 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820667904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1261252608).

820667904 is an abundant number, since it is smaller than the sum of its proper divisors (1701837312).

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

820667904 is a wasteful number, since it uses less digits than its factorization.

820667904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756 (or 740 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 42.

The square root of 820667904 is about 28647.3018624791. The cubic root of 820667904 is about 936.2442200043.

The spelling of 820667904 in words is "eight hundred twenty million, six hundred sixty-seven thousand, nine hundred four".