81228990050 has 48 divisors (see below), whose sum is σ = 162870487080. Its totient is φ = 29962275840.

The previous prime is 81228990041. The next prime is 81228990061. The reversal of 81228990050 is 5009982218.

It is a Cunningham number, because it is equal to 285007²+1.

It can be written as a sum of positive squares in 12 ways, for example, as 996728041 + 80232262009 = 31571^2 + 283253^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81228989983 and 81228990010.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 593924 + ... + 717776.

Almost surely, 2^81228990050 is an apocalyptic number.

81228990050 is an abundant number, since it is smaller than the sum of its proper divisors (81641497030).

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

81228990050 is a wasteful number, since it uses less digits than its factorization.

81228990050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124887 (or 124882 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 44.

The spelling of 81228990050 in words is "eighty-one billion, two hundred twenty-eight million, nine hundred ninety thousand, fifty".