81497000400 has 480 divisors, whose sum is σ = 284849625600. Its totient is φ = 19840204800.

The previous prime is 81497000399. The next prime is 81497000413. The reversal of 81497000400 is 400079418.

It is a super-2 number, since 2×81497000400² (a number of 23 digits) contains 22 as substring.

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, 98307186 + ... + 98308014.

It is an arithmetic number, because the mean of its divisors is an integer number (593436720).

Almost surely, 2^81497000400 is an apocalyptic number.

81497000400 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 81497000400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142424812800).

81497000400 is an abundant number, since it is smaller than the sum of its proper divisors (203352625200).

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

81497000400 is a wasteful number, since it uses less digits than its factorization.

81497000400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1007 (or 996 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

Adding to 81497000400 its reverse (400079418), we get a palindrome (81897079818).

The spelling of 81497000400 in words is "eighty-one billion, four hundred ninety-seven million, four hundred", and thus it is an aban number.