820809402 has 32 divisors (see below), whose sum is σ = 1986498432. Its totient is φ = 220721664.

The previous prime is 820809401. The next prime is 820809403. The reversal of 820809402 is 204908028.

It is an interprime number because it is at equal distance from previous prime (820809401) and next prime (820809403).

It is not an unprimeable number, because it can be changed into a prime (820809401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 574083 + ... + 575510.

It is an arithmetic number, because the mean of its divisors is an integer number (62078076).

Almost surely, 2^820809402 is an apocalyptic number.

820809402 is an abundant number, since it is smaller than the sum of its proper divisors (1165689030).

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

820809402 is a wasteful number, since it uses less digits than its factorization.

820809402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1149622.

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 820809402 is about 28649.7714127007. The cubic root of 820809402 is about 936.2980253950.

The spelling of 820809402 in words is "eight hundred twenty million, eight hundred nine thousand, four hundred two".