81953516 has 12 divisors (see below), whose sum is σ = 144170880. Its totient is φ = 40761840.

The previous prime is 81953513. The next prime is 81953533. The reversal of 81953516 is 61535918.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 81953516.

It is not an unprimeable number, because it can be changed into a prime (81953513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52871 + ... + 54398.

It is an arithmetic number, because the mean of its divisors is an integer number (12014240).

Almost surely, 2^81953516 is an apocalyptic number.

It is an amenable number.

81953516 is a deficient number, since it is larger than the sum of its proper divisors (62217364).

81953516 is a wasteful number, since it uses less digits than its factorization.

81953516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107464 (or 107462 counting only the distinct ones).

The product of its digits is 32400, while the sum is 38.

The square root of 81953516 is about 9052.8181247609. The cubic root of 81953516 is about 434.3660400201.

It can be divided in two parts, 8195 and 3516, that added together give a palindrome (11711).

The spelling of 81953516 in words is "eighty-one million, nine hundred fifty-three thousand, five hundred sixteen".