81534965200 has 240 divisors, whose sum is σ = 213831202816. Its totient is φ = 29698099200.

The previous prime is 81534965189. The next prime is 81534965203. The reversal of 81534965200 is 256943518.

It is a super-2 number, since 2×81534965200² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81534965203) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 218592214 + ... + 218592586.

Almost surely, 2^81534965200 is an apocalyptic number.

81534965200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81534965200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106915601408).

81534965200 is an abundant number, since it is smaller than the sum of its proper divisors (132296237616).

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

81534965200 is a wasteful number, since it uses less digits than its factorization.

81534965200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 862 (or 851 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 43.

The spelling of 81534965200 in words is "eighty-one billion, five hundred thirty-four million, nine hundred sixty-five thousand, two hundred".