21100020037 has 2 divisors, whose sum is σ = 21100020038. Its totient is φ = 21100020036.

The previous prime is 21100020023. The next prime is 21100020107. The reversal of 21100020037 is 73002000112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20620672801 + 479347236 = 143599^2 + 21894^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100020037 - 2¹⁵ = 21099987269 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21100020037.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100080037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550010018 + 10550010019.

It is an arithmetic number, because the mean of its divisors is an integer number (10550010019).

Almost surely, 2^21100020037 is an apocalyptic number.

It is an amenable number.

21100020037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100020037 is an equidigital number, since it uses as much as digits as its factorization.

21100020037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84, while the sum is 16.

Adding to 21100020037 its reverse (73002000112), we get a palindrome (94102020149).

The spelling of 21100020037 in words is "twenty-one billion, one hundred million, twenty thousand, thirty-seven".