81411642 has 160 divisors (see below), whose sum is σ = 214663680. Its totient is φ = 22861440.

The previous prime is 81411619. The next prime is 81411647. The reversal of 81411642 is 24611418.

It is a happy number.

81411642 is a `hidden beast` number, since 8 + 1 + 4 + 11 + 642 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (81411647) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1893273 + ... + 1893315.

It is an arithmetic number, because the mean of its divisors is an integer number (1341648).

Almost surely, 2^81411642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81411642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107331840).

81411642 is an abundant number, since it is smaller than the sum of its proper divisors (133252038).

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

81411642 is a wasteful number, since it uses less digits than its factorization.

81411642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130 (or 121 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 81411642 is about 9022.8400185308. The cubic root of 81411642 is about 433.4065841981.

The spelling of 81411642 in words is "eighty-one million, four hundred eleven thousand, six hundred forty-two".