81400650 has 48 divisors (see below), whose sum is σ = 203510784. Its totient is φ = 21530880.

The previous prime is 81400603. The next prime is 81400661. The reversal of 81400650 is 5600418.

It is a self number, because there is not a number n which added to its sum of digits gives 81400650.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16914 + ... + 21186.

It is an arithmetic number, because the mean of its divisors is an integer number (4239808).

Almost surely, 2^81400650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81400650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101755392).

81400650 is an abundant number, since it is smaller than the sum of its proper divisors (122110134).

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

81400650 is a wasteful number, since it uses less digits than its factorization.

81400650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4415 (or 4410 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 81400650 is about 9022.2308771168. The cubic root of 81400650 is about 433.3870774893.

The spelling of 81400650 in words is "eighty-one million, four hundred thousand, six hundred fifty".