1331688820 has 48 divisors (see below), whose sum is σ = 3486607488. Its totient is φ = 415071360.

The previous prime is 1331688817. The next prime is 1331688821. The reversal of 1331688820 is 288861331.

It is a super-2 number, since 2×1331688820² = 3546790226625984800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331688821) 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, 430827 + ... + 433906.

It is an arithmetic number, because the mean of its divisors is an integer number (72637656).

Almost surely, 2^1331688820 is an apocalyptic number.

1331688820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1331688820 is an abundant number, since it is smaller than the sum of its proper divisors (2154918668).

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

1331688820 is a wasteful number, since it uses less digits than its factorization.

1331688820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 864760 (or 864758 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 1331688820 is about 36492.3117930339. The cubic root of 1331688820 is about 1100.1897248507.

The spelling of 1331688820 in words is "one billion, three hundred thirty-one million, six hundred eighty-eight thousand, eight hundred twenty".