81000037 has 2 divisors, whose sum is σ = 81000038. Its totient is φ = 81000036.

The previous prime is 81000013. The next prime is 81000041. The reversal of 81000037 is 73000018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76895361 + 4104676 = 8769^2 + 2026^2 .

It is a cyclic number.

It is not a de Polignac number, because 81000037 - 2⁷ = 80999909 is a prime.

It is a super-2 number, since 2×81000037² = 13122011988002738, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 80999978 and 81000023.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81000047) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40500018 + 40500019.

It is an arithmetic number, because the mean of its divisors is an integer number (40500019).

Almost surely, 2^81000037 is an apocalyptic number.

It is an amenable number.

81000037 is a deficient number, since it is larger than the sum of its proper divisors (1).

81000037 is an equidigital number, since it uses as much as digits as its factorization.

81000037 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 81000037 is about 9000.0020555553. The cubic root of 81000037 is about 432.6749369727.

Subtracting from 81000037 its sum of digits (19), we obtain a palindrome (81000018).

The spelling of 81000037 in words is "eighty-one million, thirty-seven", and thus it is an aban number and an uban number.