81976253990400 has 3600 divisors, whose sum is σ = 383641713463008. Its totient is φ = 16922168524800.

The previous prime is 81976253990381. The next prime is 81976253990417. The reversal of 81976253990400 is 409935267918.

81976253990400 is a `hidden beast` number, since 8 + 1 + 9 + 7 + 6 + 2 + 539 + 90 + 4 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3600).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 243252979032 + ... + 243252979368.

It is a 1-persistent number, because it is pandigital, but 2⋅81976253990400 = 163952507980800 is not.

Almost surely, 2^{81976253990400} is an apocalyptic number.

81976253990400 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 81976253990400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (191820856731504).

81976253990400 is an abundant number, since it is smaller than the sum of its proper divisors (301665459472608).

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

81976253990400 is a wasteful number, since it uses less digits than its factorization.

81976253990400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683 (or 642 counting only the distinct ones).

The product of its (nonzero) digits is 29393280, while the sum is 63.

The spelling of 81976253990400 in words is "eighty-one trillion, nine hundred seventy-six billion, two hundred fifty-three million, nine hundred ninety thousand, four hundred".