81228990052 has 24 divisors (see below), whose sum is σ = 162828068480. Its totient is φ = 34733119680.

The previous prime is 81228990041. The next prime is 81228990061. The reversal of 81228990052 is 25009982218.

It is a junction number, because it is equal to n+sod(n) for n = 81228989984 and 81228990011.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3291849 + ... + 3316432.

Almost surely, 2^81228990052 is an apocalyptic number.

It is an amenable number.

81228990052 is an abundant number, since it is smaller than the sum of its proper divisors (81599078428).

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

81228990052 is a wasteful number, since it uses less digits than its factorization.

81228990052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6608731 (or 6608729 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 46.

The spelling of 81228990052 in words is "eighty-one billion, two hundred twenty-eight million, nine hundred ninety thousand, fifty-two".