1331000021 has 8 divisors (see below), whose sum is σ = 1453021080. Its totient is φ = 1211784192.

The previous prime is 1331000017. The next prime is 1331000051. The reversal of 1331000021 is 1200001331.

It can be written as a sum of positive squares in 4 ways, for example, as 304502500 + 1026497521 = 17450^2 + 32039^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1331000021 - 2² = 1331000017 is a prime.

It is a super-2 number, since 2×1331000021² = 3543122111804000882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1330999966 and 1331000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331000051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 700316 + ... + 702213.

It is an arithmetic number, because the mean of its divisors is an integer number (181627635).

Almost surely, 2^1331000021 is an apocalyptic number.

It is an amenable number.

1331000021 is a deficient number, since it is larger than the sum of its proper divisors (122021059).

1331000021 is a wasteful number, since it uses less digits than its factorization.

1331000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1402615.

The product of its (nonzero) digits is 18, while the sum is 11.

The square root of 1331000021 is about 36482.8729817157. The cubic root of 1331000021 is about 1100.0000057851. Note that the first 5 decimals are identical.

Adding to 1331000021 its reverse (1200001331), we get a palindrome (2531001352).

The spelling of 1331000021 in words is "one billion, three hundred thirty-one million, twenty-one", and thus it is an aban number.