820400705 has 32 divisors (see below), whose sum is σ = 1057795200. Its totient is φ = 608670720.

The previous prime is 820400699. The next prime is 820400719. The reversal of 820400705 is 507004028.

It is not a de Polignac number, because 820400705 - 2⁶ = 820400641 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2672162 + ... + 2672468.

It is an arithmetic number, because the mean of its divisors is an integer number (33056100).

Almost surely, 2^820400705 is an apocalyptic number.

820400705 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

820400705 is a deficient number, since it is larger than the sum of its proper divisors (237394495).

820400705 is a wasteful number, since it uses less digits than its factorization.

820400705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689.

The product of its (nonzero) digits is 2240, while the sum is 26.

The square root of 820400705 is about 28642.6378848038. The cubic root of 820400705 is about 936.1425992500.

The spelling of 820400705 in words is "eight hundred twenty million, four hundred thousand, seven hundred five".