81435501 has 36 divisors (see below), whose sum is σ = 144050400. Its totient is φ = 44080848.

The previous prime is 81435493. The next prime is 81435527. The reversal of 81435501 is 10553418.

It is not a de Polignac number, because 81435501 - 2³ = 81435493 is a prime.

It is a super-3 number, since 3×81435501³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81435551) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3520 + ... + 13238.

It is an arithmetic number, because the mean of its divisors is an integer number (4001400).

Almost surely, 2^81435501 is an apocalyptic number.

It is an amenable number.

81435501 is a deficient number, since it is larger than the sum of its proper divisors (62614899).

81435501 is a wasteful number, since it uses less digits than its factorization.

81435501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9758 (or 9748 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 81435501 is about 9024.1620663638. The cubic root of 81435501 is about 433.4489190020.

Adding to 81435501 its reverse (10553418), we get a palindrome (91988919).

It can be divided in two parts, 814 and 35501, that added together give a triangular number (36315 = T₂₆₉).

The spelling of 81435501 in words is "eighty-one million, four hundred thirty-five thousand, five hundred one".