820321512 has 16 divisors (see below), whose sum is σ = 2050803840. Its totient is φ = 273440496.

The previous prime is 820321493. The next prime is 820321517. The reversal of 820321512 is 215123028.

It is a super-2 number, since 2×820321512² = 1345854766099932288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 34180063 = 820321512 / (8 + 2 + 0 + 3 + 2 + 1 + 5 + 1 + 2).

It is not an unprimeable number, because it can be changed into a prime (820321517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17090008 + ... + 17090055.

It is an arithmetic number, because the mean of its divisors is an integer number (128175240).

Almost surely, 2^820321512 is an apocalyptic number.

It is an amenable number.

820321512 is an abundant number, since it is smaller than the sum of its proper divisors (1230482328).

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

820321512 is a wasteful number, since it uses less digits than its factorization.

820321512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34180072 (or 34180068 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 820321512 is about 28641.2554194120. The cubic root of 820321512 is about 936.1124764389.

The spelling of 820321512 in words is "eight hundred twenty million, three hundred twenty-one thousand, five hundred twelve".