81469720 has 32 divisors (see below), whose sum is σ = 192956400. Its totient is φ = 30872448.

The previous prime is 81469711. The next prime is 81469721. The reversal of 81469720 is 2796418.

It is a self number, because there is not a number n which added to its sum of digits gives 81469720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81469721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52839 + ... + 54358.

Almost surely, 2^81469720 is an apocalyptic number.

It is an amenable number.

81469720 is an abundant number, since it is smaller than the sum of its proper divisors (111486680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81469720 is a wasteful number, since it uses less digits than its factorization.

81469720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107227 (or 107223 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 81469720 is about 9026.0578327418. The cubic root of 81469720 is about 433.5096218952.

The spelling of 81469720 in words is "eighty-one million, four hundred sixty-nine thousand, seven hundred twenty".