81918045300 has 288 divisors, whose sum is σ = 294399212800. Its totient is φ = 17124618240.

The previous prime is 81918045271. The next prime is 81918045329. The reversal of 81918045300 is 354081918.

It is an interprime number because it is at equal distance from previous prime (81918045271) and next prime (81918045329).

It is a super-2 number, since 2×81918045300² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2961936 + ... + 2989464.

Almost surely, 2^81918045300 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81918045300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147199606400).

81918045300 is an abundant number, since it is smaller than the sum of its proper divisors (212481167500).

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

81918045300 is a wasteful number, since it uses less digits than its factorization.

81918045300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27675 (or 27668 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 39.

The spelling of 81918045300 in words is "eighty-one billion, nine hundred eighteen million, forty-five thousand, three hundred".