81350190 has 64 divisors (see below), whose sum is σ = 217728000. Its totient is φ = 21614112.

The previous prime is 81350123. The next prime is 81350197. The reversal of 81350190 is 9105318.

It is a super-2 number, since 2×81350190² = 13235706826072200, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81350197) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 135511 + ... + 136109.

It is an arithmetic number, because the mean of its divisors is an integer number (3402000).

Almost surely, 2^81350190 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81350190, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108864000).

81350190 is an abundant number, since it is smaller than the sum of its proper divisors (136377810).

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

81350190 is a wasteful number, since it uses less digits than its factorization.

81350190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118 (or 1112 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 81350190 is about 9019.4340177197. The cubic root of 81350190 is about 433.2975072288.

The spelling of 81350190 in words is "eighty-one million, three hundred fifty thousand, one hundred ninety".