36991321 has 2 divisors, whose sum is σ = 36991322. Its totient is φ = 36991320.

The previous prime is 36991319. The next prime is 36991343. The reversal of 36991321 is 12319963.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22467600 + 14523721 = 4740^2 + 3811^2 .

It is an emirp because it is prime and its reverse (12319963) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 36991321 - 2¹ = 36991319 is a prime.

Together with 36991319, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (36991301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18495660 + 18495661.

It is an arithmetic number, because the mean of its divisors is an integer number (18495661).

Almost surely, 2^36991321 is an apocalyptic number.

It is an amenable number.

36991321 is a deficient number, since it is larger than the sum of its proper divisors (1).

36991321 is an equidigital number, since it uses as much as digits as its factorization.

36991321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8748, while the sum is 34.

The square root of 36991321 is about 6082.0490790522. The cubic root of 36991321 is about 333.1961287547.

The spelling of 36991321 in words is "thirty-six million, nine hundred ninety-one thousand, three hundred twenty-one".