21173268037 has 2 divisors, whose sum is σ = 21173268038. Its totient is φ = 21173268036.

The previous prime is 21173267893. The next prime is 21173268041. The reversal of 21173268037 is 73086237112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20980363716 + 192904321 = 144846^2 + 13889^2 .

It is a cyclic number.

It is not a de Polignac number, because 21173268037 - 2²³ = 21164879429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21173268937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10586634018 + 10586634019.

It is an arithmetic number, because the mean of its divisors is an integer number (10586634019).

Almost surely, 2^21173268037 is an apocalyptic number.

It is an amenable number.

21173268037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21173268037 is an equidigital number, since it uses as much as digits as its factorization.

21173268037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84672, while the sum is 40.

The spelling of 21173268037 in words is "twenty-one billion, one hundred seventy-three million, two hundred sixty-eight thousand, thirty-seven".