1321012100 has 18 divisors (see below), whose sum is σ = 2866596474. Its totient is φ = 528404800.

The previous prime is 1321012067. The next prime is 1321012103. The reversal of 1321012100 is 12101231.

It can be written as a sum of positive squares in 3 ways, for example, as 7529536 + 1313482564 = 2744^2 + 36242^2 .

It is not an unprimeable number, because it can be changed into a prime (1321012103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6604961 + ... + 6605160.

Almost surely, 2^1321012100 is an apocalyptic number.

1321012100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321012100 is an abundant number, since it is smaller than the sum of its proper divisors (1545584374).

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

1321012100 is a wasteful number, since it uses less digits than its factorization.

1321012100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13210135 (or 13210128 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 1321012100 is about 36345.7301481206. The cubic root of 1321012100 is about 1097.2416011200.

Adding to 1321012100 its reverse (12101231), we get a palindrome (1333113331).

The spelling of 1321012100 in words is "one billion, three hundred twenty-one million, twelve thousand, one hundred".