81929953 has 16 divisors (see below), whose sum is σ = 100548864. Its totient is φ = 65157120.

The previous prime is 81929927. The next prime is 81929963. The reversal of 81929953 is 35992918.

It is not a de Polignac number, because 81929953 - 2¹⁷ = 81798881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81929963) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3601 + ... + 13297.

It is an arithmetic number, because the mean of its divisors is an integer number (6284304).

Almost surely, 2^81929953 is an apocalyptic number.

It is an amenable number.

81929953 is a deficient number, since it is larger than the sum of its proper divisors (18618911).

81929953 is a wasteful number, since it uses less digits than its factorization.

81929953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9792.

The product of its digits is 174960, while the sum is 46.

The square root of 81929953 is about 9051.5166132533. The cubic root of 81929953 is about 434.3244068742.

It can be divided in two parts, 8192 and 9953, that added together give a triangular number (18145 = T₁₉₀).

The spelling of 81929953 in words is "eighty-one million, nine hundred twenty-nine thousand, nine hundred fifty-three".