81163607040 has 880 divisors, whose sum is σ = 310444941312. Its totient is φ = 20233027584.

The previous prime is 81163607039. The next prime is 81163607051. The reversal of 81163607040 is 4070636118.

81163607040 is a `hidden beast` number, since 8 + 1 + 1 + 6 + 3 + 607 + 0 + 40 = 666.

It is a super-2 number, since 2×81163607040² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 81163606986 and 81163607004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 639083457 + ... + 639083583.

Almost surely, 2^81163607040 is an apocalyptic number.

81163607040 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 81163607040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155222470656).

81163607040 is an abundant number, since it is smaller than the sum of its proper divisors (229281334272).

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

81163607040 is a wasteful number, since it uses less digits than its factorization.

81163607040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 81163607040 in words is "eighty-one billion, one hundred sixty-three million, six hundred seven thousand, forty".