81124070400 has 528 divisors, whose sum is σ = 299760714880. Its totient is φ = 21499084800.

The previous prime is 81124070399. The next prime is 81124070449. The reversal of 81124070400 is 407042118.

81124070400 is a `hidden beast` number, since 8 + 11 + 240 + 7 + 0 + 400 = 666.

It is a super-2 number, since 2×81124070400² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 166578957 + ... + 166579443.

Almost surely, 2^81124070400 is an apocalyptic number.

81124070400 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 81124070400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149880357440).

81124070400 is an abundant number, since it is smaller than the sum of its proper divisors (218636644480).

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

81124070400 is a wasteful number, since it uses less digits than its factorization.

81124070400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 767 (or 738 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The spelling of 81124070400 in words is "eighty-one billion, one hundred twenty-four million, seventy thousand, four hundred".