81613062400 has 81 divisors (see below), whose sum is σ = 202061665533. Its totient is φ = 32636083200.

The previous prime is 81613062397. The next prime is 81613062449. The reversal of 81613062400 is 426031618.

It is a happy number.

The square root of 81613062400 is 285680.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 29380702464 + 52232359936 = 171408^2 + 228544^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22852615 + ... + 22856185.

Almost surely, 2^81613062400 is an apocalyptic number.

81613062400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

81613062400 is the 285680-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81613062400

81613062400 is an abundant number, since it is smaller than the sum of its proper divisors (120448603133).

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

81613062400 is an frugal number, since it uses more digits than its factorization.

81613062400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7168 (or 3578 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The spelling of 81613062400 in words is "eighty-one billion, six hundred thirteen million, sixty-two thousand, four hundred".