81130633 has 2 divisors, whose sum is σ = 81130634. Its totient is φ = 81130632.

The previous prime is 81130619. The next prime is 81130657. The reversal of 81130633 is 33603118.

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., 57198969 + 23931664 = 7563^2 + 4892^2 .

It is a cyclic number.

It is not a de Polignac number, because 81130633 - 2¹³ = 81122441 is a prime.

It is a super-2 number, since 2×81130633² = 13164359221961378, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81130598 and 81130607.

It is not a weakly prime, because it can be changed into another prime (81130433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40565316 + 40565317.

It is an arithmetic number, because the mean of its divisors is an integer number (40565317).

Almost surely, 2^81130633 is an apocalyptic number.

It is an amenable number.

81130633 is a deficient number, since it is larger than the sum of its proper divisors (1).

81130633 is an equidigital number, since it uses as much as digits as its factorization.

81130633 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 81130633 is about 9007.2544651520. The cubic root of 81130633 is about 432.9073454070.

The spelling of 81130633 in words is "eighty-one million, one hundred thirty thousand, six hundred thirty-three".