81950400 has 336 divisors, whose sum is σ = 342676480. Its totient is φ = 18662400.

The previous prime is 81950383. The next prime is 81950411. The reversal of 81950400 is 405918.

It is a tau number, because it is divible by the number of its divisors (336).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 302265 + ... + 302535.

Almost surely, 2^81950400 is an apocalyptic number.

81950400 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 81950400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171338240).

81950400 is an abundant number, since it is smaller than the sum of its proper divisors (260726080).

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

81950400 is a wasteful number, since it uses less digits than its factorization.

81950400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 81950400 is about 9052.6460220203. The cubic root of 81950400 is about 434.3605348598.

The spelling of 81950400 in words is "eighty-one million, nine hundred fifty thousand, four hundred".