81400609333440 has 280 divisors, whose sum is σ = 292541413282272. Its totient is φ = 21483046748160.

The previous prime is 81400609333387. The next prime is 81400609333487. The reversal of 81400609333440 is 4433390600418.

81400609333440 is a `hidden beast` number, since 8 + 1 + 4 + 0 + 0 + 609 + 3 + 3 + 34 + 4 + 0 = 666.

It is a super-2 number, since 2×81400609333440² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 13673676 + ... + 18702155.

Almost surely, 2^{81400609333440} is an apocalyptic number.

81400609333440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81400609333440 is an abundant number, since it is smaller than the sum of its proper divisors (211140803948832).

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

81400609333440 is a wasteful number, since it uses less digits than its factorization.

81400609333440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32375957 (or 32375938 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 45.

Adding to 81400609333440 its reverse (4433390600418), we get a palindrome (85833999933858).

The spelling of 81400609333440 in words is "eighty-one trillion, four hundred billion, six hundred nine million, three hundred thirty-three thousand, four hundred forty".