81404938452 has 48 divisors (see below), whose sum is σ = 190439424000. Its totient is φ = 27064393440.

The previous prime is 81404938451. The next prime is 81404938457. The reversal of 81404938452 is 25483940418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81404938451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15899949 + ... + 15905067.

It is an arithmetic number, because the mean of its divisors is an integer number (3967488000).

Almost surely, 2^81404938452 is an apocalyptic number.

It is an amenable number.

81404938452 is an abundant number, since it is smaller than the sum of its proper divisors (109034485548).

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

81404938452 is a wasteful number, since it uses less digits than its factorization.

81404938452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8316 (or 8314 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 48.

The spelling of 81404938452 in words is "eighty-one billion, four hundred four million, nine hundred thirty-eight thousand, four hundred fifty-two".