81898635 has 32 divisors (see below), whose sum is σ = 161280000. Its totient is φ = 34558848.

The previous prime is 81898633. The next prime is 81898669. The reversal of 81898635 is 53689818.

81898635 = 1327² + 1328² + ... + 1371².

It is not a de Polignac number, because 81898635 - 2¹ = 81898633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81898633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28635 + ... + 31364.

It is an arithmetic number, because the mean of its divisors is an integer number (5040000).

Almost surely, 2^81898635 is an apocalyptic number.

81898635 is a deficient number, since it is larger than the sum of its proper divisors (79381365).

81898635 is a wasteful number, since it uses less digits than its factorization.

81898635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60027.

The product of its digits is 414720, while the sum is 48.

The square root of 81898635 is about 9049.7864615691. The cubic root of 81898635 is about 434.2690591664.

The spelling of 81898635 in words is "eighty-one million, eight hundred ninety-eight thousand, six hundred thirty-five".