2691631321 has 2 divisors, whose sum is σ = 2691631322. Its totient is φ = 2691631320.

The previous prime is 2691631307. The next prime is 2691631337. The reversal of 2691631321 is 1231361962.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2177248921 + 514382400 = 46661^2 + 22680^2 .

It is a cyclic number.

It is not a de Polignac number, because 2691631321 - 2¹⁷ = 2691500249 is a prime.

It is a super-3 number, since 3×2691631321³ (a number of 29 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (2691641321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1345815660 + 1345815661.

It is an arithmetic number, because the mean of its divisors is an integer number (1345815661).

Almost surely, 2^2691631321 is an apocalyptic number.

It is an amenable number.

2691631321 is a deficient number, since it is larger than the sum of its proper divisors (1).

2691631321 is an equidigital number, since it uses as much as digits as its factorization.

2691631321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 34.

The square root of 2691631321 is about 51880.9340798718. The cubic root of 2691631321 is about 1391.0364956883.

The spelling of 2691631321 in words is "two billion, six hundred ninety-one million, six hundred thirty-one thousand, three hundred twenty-one".